Image forming optical system and electronic image pickup apparatus using image forming optical system

ABSTRACT

In an image forming optical system having a positive lens group, a negative lens group, and an aperture stop, the negative lens group is disposed at an image side of the of the aperture stop,
         the negative lens group has a cemented lens which is formed by cementing a plurality of lenses, and   in a rectangular coordinate system in which, a horizontal axis is let to be Nd and a vertical axis is let to be νd, when a straight line indicated by Nd=α×νd+β (where, α=−0.017) is set,   Nd and νd of at least one lens forming the cemented lens are included in both of areas namely, an area which is determined by a line when a lower limit value is in a range of a following conditional expression (1), and a line when an upper limit value is in a range of the following conditional expression (1), and an area determined by following conditional expressions (2) and (3).
 
1.45&lt;β&lt;2.15  (1)
 
1.30&lt;Nd&lt;2.20  (2)
 
3&lt;νd&lt;12  (3)
       

     Here, Nd denotes a refractive index, and νd denotes an Abbe&#39;s number.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is based upon and claims the benefit of priority from the prior Japanese Patent Application Nos. 2005-264635 filed on Sep. 13, 2005, 2005-264643 filed on Sep. 13, 2005, 2006-241564 filed on Sep. 6, 2006, and 2006-241590 filed on Sep. 6, 2006, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to an image forming optical system which is used in an extremely small image pickup module, and an electronic image pickup apparatus which includes the image forming optical system.

BACKGROUND ART

In recent years, a digital camera has been widely used as a next generation camera replacing a silver salt 35 mm film camera. Recently, there has been an increasing reduction in a size, and thinning of a digital camera. Moreover, a camera function (hereinafter called as an ‘image pickup module’) has been mounted even in a portable telephone, the use of which has also been increasing widely. For mounting this image pickup module in the portable telephone, an optical system has to be smaller and thinner than an optical system of the digital camera. Particularly, in a zoom lens, the reduction in size and the thinning have been sought. However, a zoom lens having a size reduced to be capable of being mounted in the portable telephone has not been known much.

As a typical means for reducing the size and thinning the zoom lens, the following two means can be taken into consideration. In other words,

A. To use a collapsible lens barrel, and to accommodate the optical system in a thickness (depth) of a casing. This collapsible lens barrel is a lens barrel having a structure in which, the optical system is protruded from a camera casing at the time of taking a picture, and is accommodated in the camera while carrying.

B. To accommodate the optical system in a direction of width or in a direction of height of the casing by adopting a dioptric system. This dioptric system is an optical system having a structure in which, an optical path (optical axis) of the optical system is folded by a reflecting optical element such as a mirror or a prism.

However, in a structure in which the abovementioned means A is used, the number of lenses forming the optical system or the number of movable lens groups is still large, and it is difficult to carry out the reduction in the size, and the thinning of the casing.

Moreover, in a structure in which the abovementioned means B is used, it is easy to make the casing thin as compared to a case in which the means in the abovementioned A is used, but an amount of movement of the movable lens group at the time of zooming, and the number of lenses forming the optical system tend to increase. Therefore, volumetrically, it is not at all suitable for the reduction in size.

DISCLOSURE OF THE INVENTION

An image forming optical system according to the present invention is characterized in that, in an image forming optical system having a positive lens group, a negative lens group, and an aperture stop,

the negative lens group is disposed at an image side of the aperture stop,

the negative lens group has a cemented lens which is formed by cementing a plurality of lenses, and

in a rectangular coordinate system in which, a horizontal axis is let to be Nd and a vertical axis is let to be νd, when a straight line indicated by Nd=α×νd+β (where, α=−0.017) is set,

Nd and νd of at least one lens forming the cemented lens are included in both of areas namely, an area which is determined by a line when a lower limit value is in a range of a following conditional expression (1a), and a line when an upper limit value is in a range of the following conditional expression (1a), and an area determined by following conditional expressions (2a) and (3a) 1.45<β<2.15  (1a) 1.30<Nd<2.20  (2a) 3<νd<12  (3a)

Here, Nd denotes a refractive index, and νd denotes an Abbe's number.

Moreover, an image forming optical system according to the present invention is characterized in that, in an image forming optical system having a positive lens group, a negative lens group, and an aperture stop,

the negative lens group is disposed at the image side of the aperture stop,

the negative lens group has a cemented lens which is formed by cementing a plurality of lenses, and

in a rectangular coordinate system in which, a horizontal axis is let to be Nd and a vertical axis is let to be νd, when a straight line indicated by Nd=α×νd+β (where, α=−0.017) is set,

Nd and νd of at least one lens forming the cemented lens are included in both of areas namely, an area which is determined by a line when a lower limit value is in a range of a following conditional expression (1b), and a line when an upper limit value is in a range of the following conditional expression (1b), and an area determined by following conditional expressions (2b) and (3b) 1.45<β<2.15  (1b) 1.58<Nd<2.20  (2b) 3<νd<40  (3b)

Here, Nd denotes a refractive index, and νd denotes an Abbe's number.

Moreover, an electronic image pickup apparatus of the present invention is characterized in that the electronic image pickup apparatus includes an image forming optical system mentioned in any one above, an electronic image pickup element, and an image processing means which is capable of processing image data obtained by image pickup by the electronic image pickup element, of an image which is formed through the image forming optical system, and outputting image data in which, a shape is changed upon processing, and in which the image forming optical system is a zoom lens, and the zoom lens satisfies a following conditional expression at a time of infinite object point focusing. 0.7<y ₀₇/(fw·tan ω_(07w))<0.96

where, y₀₇ is indicated as y₀₇=0.7 y₁₀ when, in an effective image pickup surface (surface in which, image pickup is possible), a distance from a center up to a farthest point (maximum image height) is let to be y₁₀. Moreover, ω_(07w) is an angle with respect to an optical axis in a direction of an object point corresponding to an image point connecting from a center on the image pickup surface in a wide angle end up to a position of y₀₇.

According to the present invention, it is possible to achieve a thinning and a size reduction of a volume of the image forming optical system, and further to have both of a widening of an angle and a favorable correction of various aberrations in the electronic image pickup apparatus of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view along an optical axis showing an optical arrangement at the time of an infinite object point focusing at a wide angle end of a zoom lens according to a first embodiment of the present invention;

FIG. 2A, FIG. 2B, and FIG. 2C are diagrams showing a spherical aberration, an astigmatism, a distortion, and a chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the first embodiment, where, FIG. 2A shows a state at the wide angle end, FIG. 2B shows an intermediate state, and FIG. 2C shows a state at a telephoto end;

FIG. 3 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a second embodiment of the present invention;

FIG. 4A, FIG. 4B, and FIG. 4C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the second embodiment, where, FIG. 4A shows the state at the wide angle end, FIG. 4B shows the intermediate state, and FIG. 4C shows the state at the telephoto end;

FIG. 5 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a third embodiment of the present invention;

FIG. 6A, FIG. 6B, and FIG. 6C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the third embodiment, where, FIG. 6A shows the state at the wide angle end, FIG. 6B shows the intermediate state, and FIG. 6C shows the state at the telephoto end;

FIG. 7 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a fourth embodiment of the present invention;

FIG. 8A, FIG. 8B, and FIG. 8C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the fourth embodiment, where, FIG. 8A shows the state at the wide angle end, FIG. 8B shows the intermediate state, and FIG. 8C shows the state at the telephoto end;

FIG. 9 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a fifth embodiment of the present invention;

FIG. 10A, FIG. 10B, and FIG. 10C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the fifth embodiment, where, FIG. 10A shows the state at the wide angle end, FIG. 10B shows the intermediate state, and FIG. 10C shows the state at the telephoto end;

FIG. 11 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a sixth embodiment of the present invention;

FIG. 12A, FIG. 12B, and FIG. 12C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the sixth embodiment, where, FIG. 12A shows the state at the wide angle end, FIG. 12B, shows the intermediate state, and FIG. 12C shows the state at the telephoto end;

FIG. 13 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a seventh embodiment of the present invention;

FIG. 14A, FIG. 14B, and FIG. 14C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the seventh embodiment, where, FIG. 14A shows the state at the wide angle end, FIG. 14B shows the intermediate state, and FIG. 14C shows the state at the telephoto end;

FIG. 15 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to an eighth embodiment of the present invention;

FIG. 16A, FIG. 16B, and FIG. 16C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the eighth embodiment, where, FIG. 16A shows the state at the wide angle end, FIG. 16B shows the intermediate state, and FIG. 16C shows the state at the telephoto end;

FIG. 17 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a ninth embodiment of the present invention;

FIG. 18A, FIG. 18B, and FIG. 18C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the ninth embodiment, where, FIG. 18A shows the state at the wide angle end, FIG. 18B shows the intermediate state, and FIG. 18C shows the state at the telephoto end;

FIG. 19 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a tenth embodiment of the present invention;

FIG. 20A, FIG. 20B, and FIG. 20C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the tenth embodiment, where, FIG. 20A shows the state at the wide angle end, FIG. 20B shows the intermediate state, and FIG. 20C shows the state at the telephoto end;

FIG. 21 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to an eleventh embodiment of the present invention;

FIG. 22A, FIG. 22B, and FIG. 22C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the eleventh embodiment, where, FIG. 22A shows the state at the wide angle end, FIG. 22B shows the intermediate state, and FIG. 22C shows the state at the telephoto end;

FIG. 23 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twelfth embodiment of the present invention;

FIG. 24A, FIG. 24B, and FIG. 24C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twelfth embodiment, where, FIG. 24A shows the state at the wide angle end, FIG. 24B shows the intermediate state, and FIG. 24C shows the state at the telephoto end;

FIG. 25 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirteenth embodiment of the present invention;

FIG. 26A, FIG. 26B, and FIG. 26C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirteenth embodiment, where FIG. 26A shows the state at the wide angle end, FIG. 26B shows the intermediate state, and FIG. 26C shows the state at the telephoto end;

FIG. 27 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a fourteenth embodiment of the present invention;

FIG. 28A, FIG. 28B, and FIG. 28C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the fourteenth embodiment, where, FIG. 28A shows the state at the wide angle end, FIG. 28B shows the intermediate state, and FIG. 28C shows the state at the telephoto end;

FIG. 29 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a fifteenth embodiment of the present invention;

FIG. 30A, FIG. 30B, and FIG. 30C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the fifteenth embodiment, where, FIG. 30A shows the state at the wide angle end, FIG. 30B shows the intermediate state, and FIG. 30C shows the state at the telephoto end;

FIG. 31 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a sixteenth embodiment of the present invention;

FIG. 32A, FIG. 32B, and FIG. 32C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the sixteenth embodiment, where, FIG. 32A shows the state at the wide angle end, FIG. 32B shows the intermediate state, and FIG. 32C shows the state at the telephoto end;

FIG. 33 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a seventeenth embodiment of the present invention;

FIG. 34A, FIG. 34B, and FIG. 34C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the seventeenth embodiment, where, FIG. 34A shows the state at the wide angle end, FIG. 34B shows the intermediate state, and FIG. 34C shows the state at the telephoto end;

FIG. 35 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to an eighteenth embodiment of the present invention;

FIG. 36A, FIG. 36B, and FIG. 36C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the eighteenth embodiment, where, FIG. 36A shows the state at the wide angle end, FIG. 36B shows the intermediate state, and FIG. 36C shows the state at the telephoto end;

FIG. 37 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a nineteenth embodiment of the present invention;

FIG. 38A, FIG. 38B, and FIG. 38C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the nineteenth embodiment, where, FIG. 38A shows the state at the wide angle end, FIG. 38B shows the intermediate state, and FIG. 38C shows the state at the telephoto end;

FIG. 39 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twentieth embodiment of the present invention;

FIG. 40A, FIG. 40B, and FIG. 40C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twentieth embodiment, where, FIG. 40A shows the state at the wide angle end, FIG. 40B shows the intermediate state, and FIG. 40C shows the state at the telephoto end;

FIG. 41 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty first embodiment of the present invention;

FIG. 42A, FIG. 42B, and FIG. 42C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty first embodiment, where, FIG. 42A shows the state at the wide angle end, FIG. 42B shows the intermediate state, and FIG. 42C shows the state at the telephoto end;

FIG. 43 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty second embodiment of the present invention;

FIG. 44A, FIG. 44B, and FIG. 44C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty second embodiment, where, FIG. 44A shows the state at the wide angle end, FIG. 44B shows the intermediate state, and FIG. 44C shows the state at the telephoto end;

FIG. 45 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty third embodiment of the present invention;

FIG. 46A, FIG. 46B, and FIG. 46C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty third embodiment, where, FIG. 46A shows the state at the wide angle end, FIG. 46B shows the intermediate state, and FIG. 46C shows the state at the telephoto end;

FIG. 47 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty fourth embodiment of the present invention;

FIG. 48A, FIG. 48B, and FIG. 48C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty fourth embodiment, where, FIG. 48A shows the state at the wide angle end, FIG. 48B shows the intermediate state, and FIG. 48C shows the state at the telephoto end;

FIG. 49 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty fifth embodiment of the present invention;

FIG. 50A, FIG. 50B, and FIG. 50C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty fifth embodiment, where, FIG. 50A shows the state at the wide angle end, FIG. 50B shows the intermediate state, and FIG. 50C shows the state at the telephoto end;

FIG. 51 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty sixth embodiment of the present invention;

FIG. 52A, FIG. 52B, and FIG. 52C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty sixth embodiment, where, FIG. 52A shows the state at the wide angle end, FIG. 52B shows the intermediate state, and FIG. 52C shows the state at the telephoto end;

FIG. 53 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty seventh embodiment of the present invention;

FIG. 54A, FIG. 54B, and FIG. 54C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty seventh embodiment, where, FIG. 54A shows the state at the wide angle end, FIG. 54B shows the intermediate state, and FIG. 54C shows the state at the telephoto end;

FIG. 55 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty eighth embodiment of the present invention;

FIG. 56A, FIG. 56B, and FIG. 56C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty eighth embodiment, where, FIG. 56A shows the state at the wide angle end, FIG. 56B shows the intermediate state, and FIG. 56C shows the state at the telephoto end;

FIG. 57 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty ninth embodiment of the present invention;

FIG. 58A, FIG. 58B, and FIG. 58C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty ninth embodiment, where, FIG. 58A shows the state at the wide angle end, FIG. 58B shows the intermediate state, and FIG. 58C shows the state at the telephoto end;

FIG. 59 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirtieth embodiment of the present invention;

FIG. 60A, FIG. 60B, and FIG. 60C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirtieth embodiment, where, FIG. 60A shows the state at the wide angle end, FIG. 60B shows the intermediate state, and FIG. 60C shows the state at the telephoto end;

FIG. 61 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty first embodiment of the present invention;

FIG. 62A, FIG. 62B, and FIG. 62C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty first embodiment, where, FIG. 62A shows the state at the wide angle end, FIG. 62B shows the intermediate state, and FIG. 62C shows the state at the telephoto end;

FIG. 63 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty second embodiment of the present invention;

FIG. 64A, FIG. 64B, and FIG. 64C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty second embodiment, where, FIG. 64A shows the state at the wide angle end, FIG. 64B shows the intermediate state, and FIG. 64C shows the state at the telephoto end;

FIG. 65 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty third embodiment of the present invention;

FIG. 66A, FIG. 66B, and FIG. 66C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty third embodiment, where, FIG. 66A shows the state at the wide angle end, FIG. 66B shows the intermediate state, and FIG. 66C shows the state at the telephoto end;

FIG. 67 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty fourth embodiment of the present invention;

FIG. 68A, FIG. 68B, and FIG. 68C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty fourth embodiment, where, FIG. 68A shows the state at the wide angle end, FIG. 68B shows the intermediate state, and FIG. 68C shows the state at the telephoto end;

FIG. 69 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty fifth embodiment of the present invention;

FIG. 70A, FIG. 70B, and FIG. 70C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty fifth embodiment, where, FIG. 70A shows the state at the wide angle end, FIG. 70B shows the intermediate state, and FIG. 70C shows the state at the telephoto end;

FIG. 71 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty sixth embodiment of the present invention;

FIG. 72A, FIG. 72B, and FIG. 72C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty sixth embodiment, where, FIG. 72A shows the state at the wide angle end, FIG. 72B shows the intermediate state, and FIG. 72C shows the state at the telephoto end;

FIG. 73 is a cross-sectional view along the optical axis showing an optical arrangement at the wide angle end of a zoom lens according to a thirty seventh embodiment of the present invention;

FIG. 74A, FIG. 74B, and FIG. 74C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty seventh embodiment, where, FIG. 74A shows the state at the wide angle end, FIG. 74B shows the intermediate state, and FIG. 74C shows the state at the telephoto end;

FIG. 75 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty eighth embodiment of the present invention;

FIG. 76A, FIG. 76B, and FIG. 76C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty eighth embodiment, where, FIG. 76A shows the state at the wide angle end, FIG. 76B shows the intermediate state, and FIG. 76C shows the state at the telephoto end;

FIG. 77 is a frontward perspective view showing an appearance of a digital camera 40 in which, a zoom optical system according to the present invention is incorporated;

FIG. 78 is a rearward perspective view of the digital camera 40;

FIG. 79 is a cross-sectional view showing an optical arrangement of the digital camera 40;

FIG. 80 is a frontward perspective view of a personal computer 300 with its cover opened, which is an example of an information processing apparatus in which, the zoom optical system of the present invention is built-in as an objective optical system;

FIG. 81 is a cross-sectional view of a photographic optical system 303 of the personal computer 300;

FIG. 82 is a side view of the personal computer 300; and

FIG. 83A, FIG. 83B, and FIG. 83C are diagrams showing a portable telephone which is an example of the information processing apparatus in which, the zoom optical system of the present invention is built-in as the taking optical system, where, FIG. 83A is a front view of a portable telephone 400, FIG. 83B is a side view of the portable telephone 400, and FIG. 83C is a cross-sectional view of a taking optical system 405.

BEST MODE FOR CARRYING OUT THE INVENTION

Prior to description of embodiments, an action and an effect of the present invention will be described below.

An image forming optical system of the present invention, where the image forming optical system includes a positive lens group, a negative lens group, and an aperture stop, has a basic structure in which the negative lens group is disposed at an image side of the aperture stop, and the negative lens group includes a cemented lens which is formed by cementing a plurality of lenses.

In this manner, in the basic structure, since the cemented lens is used in the negative lens group which is at the image side of the aperture stop, a change in a longitudinal chromatic aberration in a zoom lens, at the time zooming, is easily suppressed. Moreover, with a fewer number of lenses, it is possible to suppress sufficiently an occurrence of color spreading over a zoom range. Moreover, although an existence of the negative lens group at the image side of the aperture stop brings about a substantial effect in shortening the entire length, the thickness militates against shortening the entire length when the optical system is collapsed. However, in this basic structure, since the cemented lens can be formed to be thin, it is possible to make thin the negative lens group at the image side of the aperture stop. As a result, it is possible to realize an optical system which is thin and has a short length.

Further, in the abovementioned basic structure, it is preferable that at least one lens forming the cemented lens has the following characteristics. In other words, in a rectangular coordinate system in which, a horizontal axis is let to be Nd and a vertical axis is let to be νd, when a straight line indicated by Nd=α×νd+β (where, α=−0.017) is set, it is desirable that Nd and νd of at least one lens forming the cemented lens are included in both of areas namely, an area which is determined by a line when a lower limit value is in a range of a following conditional expression (1a), and a line when an upper limit value is in a range of the following conditional expression (1a), and an area determined by following conditional expressions (2a) and (3a). 1.45<β<2.15  (1a) 1.30<Nd<2.20  (2a) 3<νd<12  (3a)

Here, Nd denotes a refractive index, and νd denotes an Abbe's number.

Here, a glass means a lens material such as a glass and a resin. Moreover, as a cemented lens, a lens in which a plurality of lenses made of a glass selected appropriately is cemented, is used.

When a value is lower than the lower limit value in the conditional expression (1a), since a refractive index is low, an effect when an aspheric surface is provided on a side which is in contact with air is small, and a correction of a spherical aberration, a coma aberration, and a distortion becomes difficult. Or, since the Abbe's number is low, a correction of a chromatic aberration, as an extremely thin cemented lens is possible, but when the side in contact with air is made to be an aspheric surface, a chromatic coma and a chromatic aberration of magnification of high order are susceptible to occur, and a degree of freedom of an aberration correction is decreased.

When a value is higher than an upper limit value in the conditional expression (1a), since a power and a thickness of the cemented lens is required to be more than a certain magnitude for the correction of the chromatic aberration, it becomes susceptible to be effected by optical characteristics which depend on an environment of the material.

When a value is lower than a lower limit value in the conditional expression (2a), the effect when the aspheric surface is provided on the side which is in contact with air is small, and the correction of the spherical aberration, the coma aberration, and the distortion becomes difficult.

When a value is higher than an upper limit value in the conditional expression (2a), in a case of a material which includes organic properties, when the refractive index is excessively high, a temperature variance becomes excessively high, and optical characteristics which depend on the environment are susceptible to become unstable. Moreover, a reflectivity becomes excessively high, and a ghost is susceptible to occur even when coating is optimized.

When a value is lower than a lower limit value in the conditional expression (3a), the correction of the chromatic aberration, as an extremely thin cemented lens is possible, but when the side in contact with air is made to be an aspheric surface, the chromatic coma and the chromatic aberration of magnification of high order are susceptible to occur, and the degree of freedom of the aberration correction is decreased.

When a value is higher than an upper limit value in the conditional expression (3a), it is necessary to enhance a refracting power of the cemented lens for correcting the chromatic aberration, and it is advantageous for a correction of a Petzval's sum, but it becomes susceptible to be effected by the optical characteristics which depend on the environment of the material.

It is more preferable when a following conditional expression (1a′) is satisfied. 1.48<β<2.04  (1a′)

Furthermore, it is even more preferable when a following conditional expression (1a″) is satisfied. 1.50<β<2.00  (1a″)

Moreover, it is more preferable when a following conditional expression (2a′) is satisfied. 1.58<Nd<2.10  (2a′)

Furthermore, it is even more preferable when a following conditional expression (2a″) is satisfied. 1.63<Nd<1.95  (2a″)

Moreover, it is more preferable when a following conditional expression (3a′) is satisfied. 5<νd<10  (3a′)

Furthermore, it is even more preferable when a following conditional expression (3a″) is satisfied. 6<νd<9  (3a″)

Or, in the abovementioned basic structure, it is preferable that at least one lens forming the cemented lens has the following characteristics. In other words, in a rectangular coordinate system in which, a horizontal axis is let to be Nd and a vertical axis is let to be νd, when a straight line indicated by Nd=α×νd+β (where, α=−0.017) is set, Nd and νd of at least one lens forming the cemented lens is included in both of areas namely, an area which is determined by a line when a lower limit value is in a range of a following conditional expression (1b), and a line when an upper limit value is in a range of the following conditional expression (1b), and an area determined by following conditional expressions (2b) and (3b). 1.45<β<2.15  (1b) 1.58<Nd<2.20  (2b) 3<νd<40  (3b)

Here, Nd denotes the refractive index, and νd denotes the Abbe's number.

When a value is lower than a lower limit value in the conditional expression (1b), since the refractive index is low, the effect when the aspheric surface is provided on the side which is in contact with air is small, and the correction of the spherical aberration, the coma aberration, and the distortion becomes difficult. Or, since the Abbe's number is low, the correction of the chromatic aberration, as an extremely thin cemented lens is possible, but when the side in contact with air is made to be an aspheric surface, the chromatic coma, and the chromatic aberration of magnification of high order are susceptible to occur, and the degree of freedom of the aberration correction is decreased.

When a value is higher than an upper limit value in the conditional expression (1b), a correction level of the chromatic aberration and the Petzval's sum become same as of a general optical glass lens, and characteristics of the present invention are not achieved.

When a value is lower than a lower limit value in the conditional expression (2b), the effect when the aspheric surface is provided on the side which is in contact with air is small, and the correction of the spherical aberration, the coma aberration, and the distortion becomes difficult.

When a value is higher than an upper limit value in the conditional expression (2b), in the case of a material which includes organic properties, when the refractive index is excessively high, the temperature variance becomes excessively high, and the optical characteristics which depend on the environment are susceptible to become unstable. Moreover, the reflectivity becomes excessively high, and a ghost is susceptible to occur even when the coating is optimized.

When a value is lower than a lower limit value in the conditional expression (3b), the correction of the chromatic aberration, as an extremely thin cemented lens is possible, but when the side in contact with air is made to be an aspheric surface, the chromatic coma and the chromatic aberration of magnification of high order are susceptible to occur, and the degree of freedom of the aberration correction is decreased.

When a value is higher than an upper limit value in the conditional expression (3b), it is necessary to enhance the refracting power of the cemented lens for correcting the chromatic aberration, and it is advantageous for the correction of the Petzval's sum, but it becomes susceptible to be effected by the optical characteristics which depend on the environment of the material.

It is more preferable when a following conditional expression (1b′) is satisfied. 1.48<β<2.04  (1b′)

Furthermore, it is even more preferable when a following conditional expression (1b″) is satisfied. 1.50<β<2.00  (1b″)

Moreover, it is more preferable when a following conditional expression (2b′) is satisfied. 1.60<Nd<2.10  (2b′)

Furthermore, it is even more preferable when a following conditional expression (2b″) is satisfied. 1.63<Nd<1.95  (2b″)

Moreover, it is more preferable when a following conditional expression (3b′) is satisfied. 5<νd<30  (3b′)

Furthermore, it is even more preferable when a following conditional expression (3b″) is satisfied. 6<νd<25  (3b″)

Moreover, it is preferable that the cemented lens is formed by a lens (hereinafter, called as a ‘predetermined lens’) having the values of Nd and νd which are included in both the areas mentioned above, and a lens other than the predetermined lens, and a center thickness along an optical axis of the predetermined lens is less than a center thickness along an optical axis of the other lens. By making such an arrangement, it is possible to realize a more favorable correction of each aberration mentioned above, and thinning of the lens group.

Moreover, the cemented lens may be a compound lens which is formed by closely adhering and hardening a resin on a lens surface (lens surface of the other lens), in order to improve a manufacturing accuracy. Here, the resin which is adhered closely and hardened corresponds to the predetermined lens.

Moreover, the cemented lens may be a compound lens which is formed by closely adhering and hardening a glass on the lens surface (lens surface of the other lens), as it is advantageous for resistance such as a light resistance and a chemical resistance. Here, the glass which is adhered closely and hardened corresponds to the predetermined lens.

Moreover, in the cemented lens, a center thickness t1 along the optical axis of the predetermined lens (one lens in which Nd and νd are included in both the areas mentioned above) may satisfy a following conditional expression (4), in order to make a size small and to carry out molding stably. 0.22<t1<2.0  (4)

It is more preferable that a following conditional expression (4′) is satisfied. 0.3<t1<1.5  (4′)

Furthermore, it is even more preferable that a following conditional expression (4″) is satisfied. 0.32<t1<1.0  (4″)

Moreover, the image forming optical system may be a zoom lens of which, a group on the closest side of an object is a positive lens group, from a viewpoint of having a high magnification of the zoom and an improvement in a brightness of the lens.

Moreover, the image forming optical system may be a zoom lens of which, a group on the closest side of an object is a negative lens group, for making the size small.

Moreover, the image forming optical system may have a prism for folding, for facilitating size reduction of an optical system with respect to a direction of taking a photo.

Moreover, in the image forming optical system, the prism may be in a group on the closest side of an object, for further facilitating thinning.

Incidentally, when a pixel size of the electronic image pickup element becomes smaller than a certain size, a component of a frequency higher than a Nyquist frequency is eliminated due to an effect of diffraction. Therefore, when this is used, it is possible to omit an optical low-pass filter. This is preferable from a point of making the entire optical system as thin as possible.

For this, it is preferable that a following conditional expression (6) is satisfied. Fw≧a(μm)  (6)

where, Fw is a full-aperture F value, and a is a distance between pixels (unit: μm) in a horizontal direction of the electronic image pickup element.

When the conditional expression (6) is satisfied, the optical low-pass filter is not required to be disposed in an optical path. Accordingly, it is possible to make the optical system small.

In a case of satisfying the conditional expression (6), it is preferable that the aperture stop is let to be open only. This means that the optical system in this case is an optical system with a constant diameter of the aperture stop all the time. Moreover, in the optical system in this case, since an operation of narrowing is not necessary, it is possible to omit a narrowing mechanism. Accordingly, the size can be made small saving that much space. When the conditional expression (6) is not satisfied, the optical low-pass filter is necessary.

Moreover, it is more preferable that a conditional expression (6′) is satisfied. Fw≧1.2a(μm)  (6′)

Furthermore, it is even more preferable that a conditional expression (6″) is satisfied. Fw≧1.4a(μm)  (6″)

Finally, an electronic image pickup apparatus will be described below. As the electronic image pickup apparatus, an electronic image pickup apparatus in which, both a thinning of depth and a widening of image angle are realized is preferable.

Here, it is assumed that an infinite object is imaged by an optical system which has no distortion. In this case, since the image which is formed has no distortion, f=y/tan ω holds.

Here, y is a height of an image point from an optical axis, f is a focal length of the image forming system, and ω is an angle with respect to an optical axis in a direction of an object point corresponding to the image point connecting from a center on an image pickup surface, up to a position of y.

On the other hand, when the optical system has a barrel distortion, f>y/tan ω holds. In other words, when f and y are let to be constant values, ω becomes a substantial value.

Therefore, in the electronic image pickup apparatus, it is preferable to use a zoom lens as the image forming optical system. As a zoom lens, particularly in a focal length near a wide angle end, an optical system having a substantial barrel distortion may be used intentionally. In this case, since a purpose is served without correcting the distortion, it is possible to achieve the widening of the image angle of the optical system. However, an image of the object is formed on the electronic image pickup element, in a state of having the barrel distortion. Therefore, in the electronic image pickup apparatus, image data obtained by the electronic image pickup element is processed by an image processing. In this process, the image data (a shape of the image data) is changed such that the barrel distortion is corrected. By changing the image data, image data which is obtained finally, takes a shape almost similar to the object. Accordingly, based on this image data, the image of the object may be output to a CRT or a printer.

Here, as the image forming optical system (zoom lens), an image forming optical system which satisfies a following conditional expression (7) at the time of the infinite object point focusing may be adopted. 0.7<y ₀₇/(fw·tan ω_(07w))<0.96  (7)

where, y₀₇ is indicated as y₀₇=0.7y₁₀ when, in an effective image pickup surface (surface in which image pickup is possible), a distance from a center up to a farthest point (maximum image height) is let to be y₁₀. Moreover, ω_(07w) is an angle with respect to an optical axis in a direction of an object point corresponding to an image point connecting from a center on the image pickup surface at a wide angle end, up to a position of y₀₇.

The conditional expression (7) mentioned above is an expression in which, a degree of the barrel distortion in a zoom wide angle end is regulated. When the conditional expression (7) is satisfied, it is possible to fetch information of the wide image angle without making the optical system enlarged. An image which is distorted to barrel shape is subjected to photoelectric conversion, and becomes image data which is distorted to barrel shape. However, on the image data which is distorted to the barrel shape, a process equivalent to a shape change of the image is carried out electrically by the image processing means which is a signal processing system of the electronic image pickup apparatus. When this process is carried out, even when the image data output from the image processing means is reproduced finally by a display apparatus, the distortion is corrected, and an image, almost similar to a shape of an object to be photographed, is achieved.

Here, when a value is higher than an upper limit value in the conditional expression (7), particularly, when a value close to 1 is to be taken, it is possible to carry out by the image processing means, a correction equivalent to a correction in which, the distortion is corrected favorably optically, but it is difficult to fetch an image over a wide angle of visibility. On the other hand, when a value is lower than a lower limit value in the conditional expression (7), a rate of enlarging in a direction of radiating in a portion around an image angle when the image distortion due to the distortion of the optical system is corrected by the image processing means, becomes excessively high. As a result of this, deterioration in a sharpness of the area around the image becomes remarkable.

On the other hand, by satisfying the conditional expression (7), it is possible to widen the angle (make an angle in a vertical direction in the distortion to be 38° or more), and to make small the optical system.

Moreover, it is more preferable when a following conditional expression (7′) is satisfied. 0.75<y ₀₇/(fw·tan ω_(07w))<0.94  (7′)

Furthermore, it is even more preferable when a following conditional expression (7″) is satisfied. 0.80<y ₀₇/(fw·tan ω_(07w))<0.92  (7″)

The image forming optical system of the present invention, even when an electronic image pickup element of a large number of pixels is used, is capable of achieving thinning and reduction in size of a volume of the image forming optical system, by satisfying or providing each of conditional expressional and structural characteristics mentioned above, and realizing a favorable correction of aberration. Moreover, the image forming optical system of the present invention is capable of providing (satisfying) in combination the conditional expressional and structural characteristics mentioned above. In this case, it is possible to achieve further reduction in size and thinning, or the favorable aberration correction. Moreover, in the electronic image pickup apparatus having the image forming optical system of the present invention, it is possible to achieve the thinning and reduction in size of the volume of the image forming optical system, and further, to have both the favorable correction of various aberrations, and widening of the angle.

Embodiments of the present invention will be described below by using the accompanying diagrams.

As a zoom lens of the present invention, a five-group structure or a four-group structure can be taken into consideration. In a zoom lens of the five-group structure, it is preferable to dispose from an object side, each lens group in order of a first lens group having a positive refracting power, a second lens group having a negative refracting power, a third lens group having a positive refracting power, a fourth lens group having a negative refracting power, and a fifth lens group having a positive refracting power.

Here, it is preferable that the first lens group includes a negative lens, a prism, and a positive lens. At this time, it is more preferable to dispose these in order of the negative lens, the prism, and the positive lens, from the object side. Moreover, the first lens group may include only one negative lens, one prism, and one positive lens.

Moreover, it is preferable that the second lens group includes a positive lens and a negative lens. At this time, it is more preferable to dispose these in order of the negative lens and the positive lens, from the object side. Moreover, the second lens group may include only one positive lens and one negative lens.

Moreover, it is preferable that the third lens group includes a positive lens and a negative lens. At this time, it is more preferable to form a cemented lens by the positive lens and the negative lens, and to dispose the cemented lens such that the positive lens is positioned at the object side. The third lens group may be formed by only one cemented lens. In this case, the cemented lens is formed by one positive lens and one negative lens.

Moreover, it is preferable that the fourth lens group includes a positive lens and a negative lens. At this time, it is more preferable to form a cemented lens by the positive lens and the negative lens, and to dispose the cemented lens such that the negative lens is positioned at the object side. Or, it is even more preferable to form the cemented lens by the negative lenses and to dispose the cemented lens such that the negative lens having a thick center-thickness is positioned at the object side. Moreover, the fourth lens group may be formed by only one cemented lens. In this case, the cemented lens is formed by two negative lenses, or by one positive lens and one negative lens.

Moreover, it is preferable that the fifth lens group includes a positive lens. At this time, it is preferable to form the fifth lens group by only one positive lens.

Moreover, in a zoom lens of the four-group structure, it is preferable to dispose each lens group in order of a first lens group having a negative refracting power, a second lens group having a positive refracting power, a third lens group having a negative refracting power, and a fourth lens group having a positive refracting power, from the object side.

Here, it is preferable that the first lens group includes a negative lens, a prism, and a cemented lens. At this time, it is more preferable to dispose these in order of the negative lens, the prism, and the cemented lens, from the object side. Moreover, it is preferable to form the cemented lens by a positive lens and a negative lens, and to dispose the cemented lens such that the positive lens is positioned at the object side. The first lens group may include only one negative lens, one prism, and one cemented lens. In this case, the cemented lens is formed by one positive lens and one negative lens.

Moreover, it is preferable that the second lens group includes a positive lens and a negative lens. At this time, it is more preferable to form a cemented lens by the positive lens and the negative lens, and to dispose the cemented lens such that the positive lens is positioned at the object side. The second lens group may be formed by only one cemented lens. In this case, the cemented lens is formed by one positive lens and one negative lens.

Moreover, it is preferable that the third lens group includes a positive lens and a negative lens. At this time, it is more preferable to form a cemented lens by the positive lens and the negative lens, and to dispose the cemented lens such that the negative lens is positioned at the object side. The third lens group may include only one cemented lens. In this case, the cemented lens is formed by one positive lens and one negative lens.

Moreover, it is preferable that the fourth lens group includes a positive lens and a negative lens. At this time, it is preferable to form a cemented lens by the positive lens and the negative lens, and to dispose the cemented lens such that the positive lens is positioned at the object side. The fourth lens group may include only one cemented lens. In this case, the cemented lens is formed by one positive lens and one negative lens.

It is possible to distribute a refracting power of one lens into two lenses. Accordingly, in each of the lens groups mentioned above, it is possible to substitute one lens by tow lenses. However, from a point of view of the reduction in size and thinning, it is preferable to let the number of lenses to be substituted by two lenses in each lens group, to be only one.

First Embodiment

FIG. 1 is a cross-sectional view along an optical axis showing an optical arrangement at the time of an infinite object point focusing at a wide angle end of a zoom lens according to a first embodiment;

FIG. 2A, FIG. 2B, and FIG. 2C are diagrams showing a spherical aberration, an astigmatism, a distortion, and a chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the first embodiment, where, FIG. 2A shows a state at the wide angle end, FIG. 2B shows an intermediate state, and FIG. 2C shows a state at a telephoto end.

The zoom lens of the first embodiment, as shown in FIG. 1, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refracting power as a whole.

The second lens group G2 includes a biconcave lens L121 and a positive meniscus lens L122 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a biconvex lens L131 and a biconcave lens L132, and has a positive refracting power as a whole.

The fourth lens group G4 includes a cemented lens which is formed by a negative meniscus lens L141 having a convex surface directed toward the object side and a positive meniscus lens L142 having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L142 having the convex surface directed toward the object side is a lens having a thin center-thickness.

The fifth lens group G5 includes a biconvex lens L151, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward an image side, the aperture stop S is fixed, the third lens group G3 moves toward the object side, the fourth lens group G4 moves once toward the image side, and then moves toward the object side, and the fifth lens group G5 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L113 in the first lens group G1, both surfaces of the biconcave lens L121 in the second lens group G2, a surface on the object side of the biconvex lens L131 and a surface on the image side of the biconcave lens L132 in the third lens group G3, a surface on the image side of the positive meniscus lens L142 having the convex surface directed toward the object side in the fourth lens group G4, and a surface on the object side of the biconvex lens L151 in the fifth lens group G5.

Next, numerical data of optical members forming the zoom lens of the first embodiment will be enumerated.

In the numerical data of the first embodiment, r1, r2, . . . denote a radius of curvature of each lens surface; d1, d2, . . . denote a thickness or an air space of each lens; νd1, νd2, . . . denote the Abbe's number for each lens; Fno. denotes F number; f denotes a focal length of an overall system; and D0 denotes a distance from the object to the first surface.

An aspheric surface shape is expressed by a following expression when a direction of an optical axis is let to be z, a direction orthogonal to the optical axis is let to be y, a conical coefficient is let to be K, and an aspheric coefficient is let to be A4, A6, A8, and A10. z=(y ² /r)/[1+{1−(1+K)(y/r)²}^(1/2) ]+A4y ⁴ +A6y ⁶ +A8y ⁸ +A10y ¹⁰

Moreover, E denotes a power of 10. These symbols of data values are common even in numerical data of embodiments which will be described later. The conical coefficient might also be denoted by k.

Next, numerical data of the first embodiment will be enumerated.

Numerical data 1 r1 = 26.557 d1 = 1 Nd1 = 1.8061 νd1 = 40.92 r2 = 10.004 d2 = 2.9 r3 = ∞ d3 = 12 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.3 r5 = 27.042 d5 = 3.54 Nd5 = 1.741 νd5 = 52.64 (Aspheric surface) r6 = −26.824 d6 = D6 r7 = −115.521 d7 = 0.8 Nd7 = 1.8061 νd7 = 40.92 (Aspheric surface) r8 = 6.039 d8 = 0.7 (Aspheric surface) r9 = 8.219 d9 = 2.2 Nd9 = 1.7552 νd9 = 27.51 r10 = 61.534 d10 = D10 r11 = Aperture stop d11 = D11 r12 = 8.050 d12 = 5.71 Nd12 = 1.6935 νd12 = 53.21 (Aspheric surface) r13 = −11.948 d13 = 0.7 Nd13 = 1.84666 νd13 = 23.78 r14 = 32.240 d14 = D14 (Aspheric surface) r15 = 21.8 d15 = 0.6 Nd15 = 1.51823 νd15 = 58.9 r16 = 10.948 d16 = 0.1 Nd16 = 1.41244 νd16 = 12.42 r17 = 11.980 d17 = D17 (Aspheric surface) r18 = 14.280 d18 = 1.8 Nd18 = 1.741 νd18 = 52.64 (Aspheric surface) r19 = −55.898 d19 = D19 r20 = ∞ d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84 r21 = ∞ d21 = 0.8 r22 = ∞ d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14 r23 = ∞ d23 = D23 Aspherical coefficients  5th surface k = 0 A4 = −1.73171E−06 A6 = 2.30891E−07 A8 = 0.00000E+00  7th surface k = 0 A4 = −3.80133E−04 A6 = 1.91619E−05 A8 = −4.14130E−07  8th surface k = 0 A4 = −8.12458E−04 A6 = 2.38978E−05 A8 = −1.03173E−06 12th surface k = 0 A4 = 1.35152E−04 A6 = 1.51360E−06 A8 = 5.39228E−08 14th surface k = 0 A4 = 7.21280E−04 A6 = 5.76577E−06 A8 = 7.71463E−07 17th surface k = 0 A4 = 1.49229E−04 A6 = −4.05344E−06 A8 = 0.00000E+00 18th surface k = 0 A4 = 3.47673E−05 A6 = 4.88008E−06 A8 = −1.88759E−07 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.017 13.716 18.012 FNO. 2.85 4.82 5.88 D6 0.8 6.96 8.38 D10 8.97 2.81 1.38 D11 11.35 3.74 1.19 D14 1.7 11.95 14.21 D17 1.46 2.01 3.34 D19 4.73 1.56 0.51 D23 1.38 1.37 1.37

Second Embodiment

FIG. 3 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a second embodiment of the present invention.

FIG. 4A, FIG. 4B, and FIG. 4C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the second embodiment, where, FIG. 4A shows the state at the wide angle end, FIG. 4B shows the intermediate state, and FIG. 4C shows the state at the telephoto end.

The zoom lens of the second embodiment, as shown in FIG. 2, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refracting power as a whole.

The second lens group G2 includes a biconcave lens L121 and a positive meniscus lens L122 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a biconvex lens L131 and a biconcave lens L132, and has a positive refracting power as a whole.

The fourth lens group G4 includes a cemented lens which is formed by a negative meniscus lens L141 having a convex surface directed toward the object side and a positive meniscus lens L142 having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L142 having the convex surface directed toward the object side is a lens having a thin center-thickness.

The fifth lens group G5 includes a positive meniscus lens L151 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward an image side, the aperture stop S is fixed, the third lens group G3 moves toward the object side, the fourth lens group G4 moves once toward the image side, and then moves toward the object side, and the fifth lens group G5 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L113 in the first lens group G1, both surfaces of the biconcave lens L121 in the second lens group G2, a surface on the object side of the biconvex lens L131 and a surface on the image side of the biconcave lens L132 in the third lens group G3, a surface on the image side of the positive meniscus lens L142 having the convex surface directed toward the object side in the fourth lens group G4, and a surface on the object side of the positive meniscus lens L151 having the convex surface directed toward the object side in the fifth lens group G5.

Next, numerical data of the second embodiment will be enumerated.

Numerical data 2 r1 = 26.496 d1 = 1 Nd1 = 1.8061 νd1 = 40.92 r2 = 9.996 d2 = 2.9 r3 = ∞ d3 = 12 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.3 r5 = 27.168 d5 = 3.54 Nd5 = 1.741 νd5 = 52.64 (Aspheric surface) r6 = −21.702 d6 = D6 r7 = −53.995 d7 = 0.8 Nd7 = 1.8061 νd7 = 40.92 (Aspheric surface) r8 = 5.765 d8 = 0.7 (Aspheric surface) r9 = 7.628 d9 = 2.2 Nd9 = 1.7552 νd9 = 27.51 r10 = 54.099 d10 = D10 r11 = Aperture stop d11 = D11 r12 = 8.731 d12 = 5.87 Nd12 = 1.6935 νd12 = 53.21 (Aspheric surface) r13 = −9.889 d13 = 0.7 Nd13 = 1.84666 νd13 = 23.78 r14 = 46.648 d14 = D14 (Aspheric surface) r15 = 12.37 d15 = 0.6 Nd15 = 1.51742 νd15 = 52.43 r16 = 12.066 d16 = 0.1 Nd16 = 1.42001 νd16 = 6.55 r17 = 13.273 d17 = D17 (Aspheric surface) r18 = 14.366 d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34 (Aspheric surface) r19 = 91.286 d19 = D19 r20 = ∞ d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84 r21 = ∞ d21 = 0.8 r22 = ∞ d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14 r23 = ∞ d23 = D23 Aspherical coefficients  5th surface k = 0 A4 = −1.77524E−05 A6 = 1.35220E−07 A8 = 0.00000E+00  7th surface k = 0 A4 = −5.85040E−05 A6 = 2.41198E−06 A8 = −9.95533E−08  8th surface k = 0 A4 = −4.62415E−04 A6 = 5.03585E−06 A8 = −8.34140E−07 12th surface k = 0 A4 = 1.64134E−04 A6 = 1.47621E−06 A8 = 4.58611E−08 14th surface k = 0 A4 = 5.87773E−04 A6 = 6.51647E−06 A8 = 3.75134E−07 17th surface k = 0 A4 = 8.08669E−05 A6 = −8.28890E−07 A8 = 0.00000E+00 18th surface k = 0 A4 = −1.76571E−05 A6 = 6.15880E−06 A8 = −1.80534E−07 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 5.998 13.7 18.004 FNO. 2.85 4.82 5.88 D6 0.8 6.92 8.4 D10 9.01 2.88 1.4 D11 11.01 3.53 1.2 D14 1.7 11.37 14.09 D17 1.55 1.9 3.15 D19 4.67 2.14 0.5 D23 1.36 1.36 1.36

Third Embodiment

FIG. 5 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a third embodiment of the present invention.

FIG. 6A, FIG. 6B, and FIG. 6C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the third embodiment, where, FIG. 6A shows the state at the wide angle end, FIG. 6B shows the intermediate state, and FIG. 6C shows the state at the telephoto end.

The zoom lens of the third embodiment, as shown in FIG. 5, has in order from the object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refracting power as a whole.

The second lens group G2 includes a biconcave lens L121 and a positive meniscus lens L122 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a biconvex lens L131 and a biconcave lens L132, and has a positive refracting power as a whole.

The fourth lens group G4 includes a cemented lens which is formed by a negative meniscus lens L141 having a convex surface directed toward the object side and a positive meniscus lens L142 having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L142 having the convex surface directed toward the object side is a lens having a thin center-thickness.

The fifth lens group G5 includes a biconvex lens L151, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward an image side, the aperture stop S is fixed, the third lens group G3 moves toward the object side, the fourth lens group G4 moves once toward the image side, and then moves toward the object side, and the fifth lens group G5 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L113 in the first lens group G1, both surfaces of the biconcave lens L121 in the second lens group G2, a surface on the object side of the biconvex lens L131 and a surface on the image side of the biconcave lens L132 in the third lens group G3, a surface on the image side of the positive meniscus lens L142 having the convex surface directed toward the object side in the fourth lens group G4, and a surface on the object side of the biconvex lens L151 in the fifth lens group G5.

Next, numerical data of the third embodiment will be enumerated.

Numerical data 3 r1 = 26.257 d1 = 1 Nd1 = 1.8061 νd1 = 40.92 r2 = 9.999 d2 = 2.9 r3 = ∞ d3 = 12 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.3 r5 = 25.860 d5 = 3.54 Nd5 = 1.741 νd5 = 52.64 (Aspheric surface) r6 = −26.388 d6 = D6 r7 = −83.928 d7 = 0.8 Nd7 = 1.8061 νd7 = 40.92 (Aspheric surface) r8 = 5.755 d8 = 0.7 (Aspheric surface) r9 = 7.952 d9 = 2.2 Nd9 = 1.7552 νd9 = 27.51 r10 = 69.069 d10 = D10 r11 = Aperture stop d11 = D11 r12 = 8.100 d12 = 5.79 Nd12 = 1.6935 νd12 = 53.21 (Aspheric surface) r13 = −11.015 d13 = 0.7 Nd13 = 1.84666 νd13 = 23.78 r14 = 35.292 d14 = D14 (Aspheric surface) r15 = 15.547 d15 = 0.6 Nd15 = 1.48749 νd15 = 70.23 r16 = 11.094 d16 = 0.1 Nd16 = 1.51824 νd16 = 12.85 r17 = 12.203 d17 = D17 (Aspheric surface) r18 = 15.707 d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34 (Aspheric surface) r19 = −252.829 d19 = D19 r20 = ∞ d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84 r21 = ∞ d21 = 0.8 r22 = ∞ d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14 r23 = ∞ d23 = D23 Aspherical coefficients  5th surface k = 0 A4 = −5.58096E−06 A6 = 2.34663E−07 A8 = 0.00000E+00  7th surface k = 0 A4 = −3.52333E−04 A6 = 1.77314E−05 A8 = −4.21441E−07  8th surface k = 0 A4 = −8.52536E−04 A6 = 2.24073E−05 A8 = −1.28129E−06 12th surface k = 0 A4 = 1.40161E−04 A6 = 1.66875E−06 A8 = 5.27383E−08 14th surface k = 0 A4 = 7.04358E−04 A6 = 6.81308E−06 A8 = 7.23678E−07 17th surface k = 0 A4 = 4.50939E−05 A6 = −2.09216E−06 A8 = 0.00000E+00 18th surface k = 0 A4 = −2.89463E−05 A6 = 7.59603E−06 A8 = −2.57963E−07 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 5.999 13.701 18.003 FNO. 2.85 4.82 5.88 D6 0.8 6.84 8.39 D10 8.99 2.95 1.4 D11 11.3 3.66 1.2 D14 1.7 11.9 14.12 D17 1.37 1.9 3.24 D19 4.7 1.61 0.5 D23 1.36 1.36 1.36

Fourth Embodiment

FIG. 7 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a fourth embodiment of the present invention.

FIG. 8A, FIG. 8B, and FIG. 8C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the fourth embodiment, where, FIG. 8A shows the state at the wide angle end, FIG. 8B shows the intermediate state, and FIG. 8C shows the state at the telephoto end.

The zoom lens of the fourth embodiment, as shown in FIG. 7, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refracting power as a whole.

The second lens group G2 includes a biconcave lens L121 and a positive meniscus lens L122 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a biconvex lens L131 and a biconcave lens L132, and has a positive refracting power as a whole.

The fourth lens group G4 includes a cemented lens which is formed by a negative meniscus lens L141 having a convex surface directed toward the object side and a positive meniscus lens L142 having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L142 having the convex surface directed toward the object side is a lens having a thin center-thickness.

The fifth lens group G5 includes a biconvex lens L151, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward an image side, the aperture stop S is fixed, the third lens group G3 moves toward the object side, the fourth lens group G4 moves once toward the image side, and then moves toward the object side, and the fifth lens group G5 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L113 in the first lens group G1, both surfaces of the biconcave lens L121 in the second lens group G2, a surface on the object side of the biconvex lens L131 and a surface on the image side of the biconcave lens L132 in the third lens group G3, a surface on the image side of the positive meniscus lens L142 having the convex surface directed toward the object side in the fourth lens group G4, and a surface on the object side of the biconvex lens L151 in the fifth lens group G5.

Next, numerical data of the fourth embodiment will be enumerated.

Numerical data 4 r1 = 26.253 d1 = 1 Nd1 = 1.8061 νd1 = 40.92 r2 = 10.003 d2 = 2.9 r3 = ∞ d3 = 12 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.3 r5 = 28.806 d5 = 3.54 Nd5 = 1.741 νd5 = 52.64 (Aspheric surface) r6 = −25.622 d6 = D6 r7 = −228.935 d7 = 0.8 Nd7 = 1.8061 νd7 = 40.92 (Aspheric surface) r8 = 5.857 d8 = 0.7 (Aspheric surface) r9 = 8.267 d9 = 2.2 Nd9 = 1.7552 νd9 = 27.51 r10 = 63.529 d10 = D10 r11 = Aperture stop d11 = D11 r12 = 8.041 d12 = 5.85 Nd12 = 1.6935 νd12 = 53.21 (Aspheric surface) r13 = −12.545 d13 = 0.7 Nd13 = 1.84666 νd13 = 23.78 r14 = 32.953 d14 = D14 (Aspheric surface) r15 = 25.26 d15 = 0.6 Nd15 = 1.54814 νd15 = 45.79 r16 = 11.772 d16 = 0.1 Nd16 = 1.54856 νd16 = 7.04 r17 = 12.596 d17 = D17 (Aspheric surface) r18 = 15.255 d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34 (Aspheric surface) r19 = −44.718 d19 = D19 r20 = ∞ d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84 r21 = ∞ d21 = 0.8 r22 = ∞ d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14 r23 = ∞ d23 = D23 Aspherical coefficients  5th surface k = 0 A4 = −2.83706E−06 A6 = 3.54530E−07 A8 = 0.00000E+00  7th surface k = 0 A4 = −7.86643E−04 A6 = 3.97737E−05 A8 = −6.87077E−07  8th surface k = 0 A4 = −1.35693E−03 A6 = 5.10859E−05 A8 = −1.40625E−06 12th surface k = 0 A4 = 1.12073E−04 A6 = 1.50035E−06 A8 = 6.45760E−08 14th surface k = 0 A4 = 7.44758E−04 A6 = −1.99790E−06 A8 = 1.14424E−06 17th surface k = 0 A4 = 1.91131E−04 A6 = −5.08202E−06 A8 = 0.00000E+00 18th surface k = 0 A4 = 9.72262E−05 A6 = 2.70387E−06 A8 = −1.95063E−07 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.003 13.694 17.997 FNO. 2.85 4.77 5.79 D6 0.8 6.89 8.38 D10 8.99 2.9 1.41 D11 11.18 3.71 1.21 D14 1.7 11.93 14.14 D17 1.41 1.97 3.22 D19 4.78 1.45 0.49 D23 1.36 1.37 1.36

Fifth Embodiment

FIG. 9 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a fifth embodiment of the present invention.

FIG. 10A, FIG. 10B, and FIG. 10C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the fifth embodiment, where, FIG. 10A shows the state at the wide angle end, FIG. 10B shows the intermediate state, and FIG. 10C shows the state at the telephoto end.

The zoom lens of the fifth embodiment, as shown in FIG. 9, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refracting power as a whole.

The second lens group G2 includes a biconcave lens L121 and a positive meniscus lens L122 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a biconvex lens L131 and a biconcave lens L132, and has a positive refracting power as a whole.

The fourth lens group G4 includes a cemented lens which is formed by a negative meniscus lens L141 having a convex surface directed toward the object side and a positive meniscus lens L142 having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L142 having the convex surface directed toward the object side is a lens having a thin center-thickness.

The fifth lens group G5 includes a positive meniscus lens L151 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward the image side, the aperture stop S is fixed, the third lens group G3 moves toward the object side, the fourth lens group G4 moves once toward the image side, and then moves toward the object side, and the fifth lens group G5 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L113 in the first lens group G1, both surfaces of the biconcave lens L121 in the second lens group G2, a surface on the object side of the biconvex lens L131 and a surface on the image side of the biconcave lens L132 in the third lens group G3, a surface on the image side of the positive meniscus lens L142 having the convex surface directed toward the object side in the fourth lens group G4, and a surface on the object side of the positive meniscus lens L151 having the convex surface directed toward the object side in the fifth lens group G5.

Next, numerical data of the fifth embodiment will be enumerated.

Numerical data 5 r1 = 25.378 d1 = 1 Nd1 = 1.8061 νd1 = 40.92 r2 = 9.203 d2 = 3.71 r3 = ∞ d3 = 12 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.3 r5 = 47.204 d5 = 3.54 Nd5 = 1.741 νd5 = 52.64 (Aspheric surface) r6 = −22.238 d6 = D6 r7 = −59.956 d7 = 0.8 Nd7 = 1.8061 νd7 = 40.92 (Aspheric surface) r8 = 6.912 d8 = 0.7 (Aspheric surface) r9 = 9.696 d9 = 2.2 Nd9 = 1.7552 νd9 = 27.51 r10 = 218.437 d10 = D10 r11 = Aperture stop d11 = D11 r12 = 7.687 d12 = 6.26 Nd12 = 1.6935 νd12 = 53.21 (Aspheric surface) r13 = −12.317 d13 = 0.7 Nd13 = 1.84666 νd13 = 23.78 r14 = 29.010 d14 = D14 (Aspheric surface) r15 = 15.343 d15 = 0.6 Nd15 = 1.58267 νd15 = 46.42 r16 = 7.801 d16 = 0.1 Nd16 = 1.65228 νd16 = 12 r17 = 7.969 d17 = D17 (Aspheric surface) r18 = 10.663 d18 = 1.8 Nd18 = 1.7725 νd18 = 49.6 (Aspheric surface) r19 = 182.013 d19 = D19 r20 = ∞ d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84 r21 = ∞ d21 = 0.8 r22 = ∞ d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14 r23 = ∞ d23 = D23 Aspherical coefficients  5th surface k = 0 A4 = 1.56293E−05 A6 = 1.88151E−07 A8 = 0  7th surface k = 0 A4 = −3.52622E−04 A6 = 1.94506E−05 A8 = −2.27135E−07  8th surface k = 0 A4 = −6.69309E−04 A6 = 1.97817E−05 A8 = −2.00038E−07 12th surface k = 0 A4 = 7.43312E−05 A6 = 1.49461E−06 A8 = 2.68705E−08 14th surface k = 0 A4 = 7.23485E−04 A6 = 9.02163E−06 A8 = 9.80727E−07 17th surface k = 0 A4 = 6.18056E−06 A6 = 2.05787E−06 A8 = 0.00000E+00 18th surface k = 0 A4 = −3.12291E−05 A6 = 9.09050E−06 A8 = −1.55608E−07 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.1 13.42 17.995 FNO. 3.37 5.23 6.58 D6 3.92 9.22 9.7 D10 12.74 2.46 0.47 D11 6.15 2.51 0.43 D14 1.57 12.09 15.5 D17 1.33 2 3.24 D19 4.75 1.4 0.53 D23 1.37 1.37 1.37

Sixth Embodiment

FIG. 11 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a sixth embodiment of the present invention.

FIG. 12A, FIG. 12B, and FIG. 12C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the sixth embodiment, where, FIG. 12A shows the state at the wide angle end, FIG. 12B shows the intermediate state, and FIG. 12C shows the state at the telephoto end.

The zoom lens of the sixth embodiment, as shown in FIG. 11, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refracting power as a whole.

The second lens group G2 includes a biconcave lens L121 and a positive meniscus lens L122 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

The third lens group G3 includes a cemented lens which his formed by a biconvex lens L131 and a biconcave lens L132, and has a positive refracting power as a whole.

The fourth lens group G4 includes a cemented lens which is formed by a negative meniscus lens L141 having a convex surface directed toward the object side and a negative meniscus lens L142 having a convex surface directed toward the object side, and has a negative refracting power as a whole. The negative meniscus lens L142 having the convex surface directed toward the object side is a lens having a thin center-thickness.

The fifth lens group G5 includes a positive meniscus lens L151 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward an image side, the aperture stop S is fixed, the third lens group G3 moves toward the object side, the fourth lens group G4 moves once toward the image side, and then moves toward the object side, and the fifth lens group G5 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L113 in the first lens group G1, both surfaces of the biconcave lens L121 in the second lens group G2, a surface on the object side of the biconvex lens L131 and a surface on the image side of the biconcave lens L132 in the third lens group G3, a surface on the image side of the negative meniscus lens L142 having the convex surface directed toward the object side in the fourth lens group G4, and a surface on the object side of the positive meniscus lens L151 having the convex surface directed toward the object side in the fifth lens group G5.

Next, numerical data of the sixth embodiment will be enumerated.

Numerical data 6 r1 = 22.245 d1 = 1 Nd1 = 1.8061 νd1 = 40.92 r2 = 8.826 d2 = 3.45 r3 = ∞ d3 = 12 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.3 r5 = 36.134 d5 = 3.54 Nd5 = 1.741 νd5 = 52.64 (Aspheric surface) r6 = −26.96 d6 = D6 r7 = −114.807 d7 = 0.8 Nd7 = 1.8061 νd7 = 40.92 (Aspheric surface) r8 = 6.407 d8 = 0.7 (Aspheric surface) r9 = 8.98 d9 = 2.2 Nd9 = 1.7552 νd9 = 27.51 r10 = 126.659 d10 = D10 r11 = Aperture stop d11 = D11 r12 = 7.716 d12 = 6.16 Nd12 = 1.6935 νd12 = 53.21 (Aspheric surface) r13 = −11.934 d13 = 0.7 Nd13 = 1.84666 νd13 = 23.78 r14 = 29.278 d14 = D14 (Aspheric surface) r15 = 11.15 d15 = 0.6 Nd15 = 1.48749 νd15 = 70.23 r16 = 6.803 d16 = 0.1 Nd16 = 1.59885 νd16 = 6.52 r17 = 6.686 d17 = D17 (Aspheric surface) r18 = 10.149 d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34 (Aspheric surface) r19 = 93.849 d19 = D19 r20 = ∞ d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84 r21 = ∞ d21 = 0.8 r22 = ∞ d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14 r23 = ∞ d23 = D23 Aspherical coefficients  5th surface k = 0 A4 = 3.04484E−05 A6 = 2.47332E−07 A8 = 0  7th surface k = 0 A4 = −3.29779E−04 A6 = 1.94880E−05 A8 = −2.30770E−07  8th surface k = 0 A4 = −6.90117E−04 A6 = 1.82143E−05 A8 = −2.09696E−07 12th surface k = 0 A4 = 7.14236E−05 A6 = 1.72782E−06 A8 = 2.44480E−08 14th surface k = 0 A4 = 6.86121E−04 A6 = 1.02728E−05 A8 = 8.39843E−07 17th surface k = 0 A4 = −8.14853E−05 A6 = 6.69357E−07 A8 = 0.00000E+00 18th surface k = 0 A4 = −7.16543E−05 A6 = 1.04773E−05 A8 = −1.54753E−07 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.1 13.42 17.995 FNO. 3.21 5.1 6.43 D6 2.85 10.17 10.67 D10 10.88 2.65 0.77 D11 6.94 2.58 0.4 D14 1.17 12.06 15.56 D17 1.33 2.02 3.28 D19 4.75 1.39 0.49 D23 1.37 1.37 1.37

Seventh Embodiment

FIG. 13 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a seventh embodiment of the present invention.

FIG. 14A, FIG. 14B, and FIG. 14C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the seventh embodiment, where, FIG. 14A shows the state at the wide angle end, FIG. 14B shows the intermediate state, and FIG. 14C shows the state at the telephoto end.

The zoom lens of the seventh embodiment, as shown in FIG. 13, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refracting power as a whole.

The second lens group G2 includes a biconcave lens L121 and a positive meniscus lens L122 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a biconvex lens L131 and a biconcave lens L132, and has a positive refracting power as a whole.

The fourth lens group G4 includes a cemented lens which is formed by a negative meniscus lens L141 having a convex surface directed toward the object side and a positive meniscus lens L142 having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L142 having the convex surface directed toward the object side is a lens having a thin center-thickness.

The fifth lens group G5 includes a positive meniscus lens L151 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward an image side, the aperture stops is fixed, the third lens group G3 moves toward the object side, the fourth lens group G4 moves once toward the image side, and then moves toward the object side, and the fifth lens group G5 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L113 in the first lens group G1, both surfaces of the biconcave lens L121 in the second lens group G2, a surface on the object side of the biconvex lens L131 and a surface on the image side of the biconcave lens L132 in the third lens group G3, a surface on the image side of the positive meniscus lens L142 having the convex surface directed toward the object side in the fourth lens group G4, and a surface on the object side of the positive meniscus lens L151 having the convex surface directed toward the object side in the fifth lens group G5.

Next, numerical data of the seventh embodiment will be enumerated.

Numerical data 7 r1 = 23.3 d1 = 1 Nd1 = 1.8061 νd1 = 40.92 r2 = 8.963 d2 = 3.66 r3 = ∞ d3 = 12 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.3 r5 = 43.373 d5 = 3.54 Nd5 = 1.741 νd5 = 52.64 (Aspheric surface) r6 = −23.569 d6 = D6 r7 = −60.807 d7 = 0.8 Nd7 = 1.8061 νd7 = 40.92 (Aspheric surface) r8 = 6.844 d8 = 0.7 (Aspheric surface) r9 = 9.537 d9 = 2.2 Nd9 = 1.7552 νd9 = 27.51 r10 = 225.725 d10 = D10 r11 = Aperture stop d11 = D11 r12 = 7.662 d12 = 6.34 Nd12 = 1.6935 νd12 = 53.21 (Aspheric surface) r13 = −11.718 d13 = 0.7 Nd13 = 1.84666 νd13 = 23.78 r14 = 28.761 d14 = D14 (Aspheric surface) r15 = 15.01 d15 = 0.6 Nd15 = 1.48749 νd15 = 70.23 r16 = 7.96 d16 = 0.1 Nd16 = 1.79525 νd16 = 9.95 r17 = 7.975 d17 = D17 (Aspheric surface) r18 = 11.632 d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34 (Aspheric surface) r19 = 234.357 d19 = D19 r20 = ∞ d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84 r21 = ∞ d21 = 0.8 r22 = ∞ d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14 r23 = ∞ d23 = D23 Aspherical coefficients  5th surface k = 0 A4 = 2.10592E−05 A6 = 2.04017E−07 A8 = 0  7th surface k = 0 A4 = −2.74185E−04 A6 = 1.68715E−05 A8 = −1.96216E−07  8th surface k = 0 A4 = −5.92738E−04 A6 = 1.71764E−05 A8 = −2.01706E−07 12th surface k = 0 A4 = 6.68932E−05 A6 = 1.80769E−06 A8 = 1.66788E−08 14th surface k = 0 A4 = 7.22351E−04 A6 = 1.11715E−05 A8 = 9.20361E−07 17th surface k = 0 A4 = −2.32260E−05 A6 = 6.22598E−07 A8 = 0.00000E+00 18th surface k = 0 A4 = −5.31997E−05 A6 = 8.76368E−06 A8 = −1.43841E−07 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.1 13.42 17.995 FNO. 3.45 5.14 6.51 D6 3.24 9.87 10.77 D10 13.65 2.39 0.92 D11 5.85 3.12 0.4 D14 1.48 11.6 14.74 D17 1.34 2.07 3.37 D19 4.75 1.33 0.4 D23 1.37 1.37 1.37

Eighth Embodiment

FIG. 15 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to an eighth embodiment of the present invention.

FIG. 16A, FIG. 16B, and FIG. 16C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the eighth embodiment, where, FIG. 16A shows the state at the wide angle end, FIG. 16B shows the intermediate state, and FIG. 16C shows the state at the telephoto end.

The zoom lens of the eighth embodiment, as shown in FIG. 15, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refracting power as a whole.

The second lens group G2 includes a biconcave lens L121 and a positive meniscus lens L122 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a biconvex lens L131 and a biconcave lens L132, and has a positive refracting power as a whole.

The fourth lens group G4 includes a cemented lens which is formed by a negative meniscus lens L141 having a convex surface directed toward the object side and a positive meniscus lens L142 having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L142 having the convex surface directed toward the object side is a lens having a thin center-thickness.

The fifth lens group G5 includes a biconvex lens L151, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward an image side, the aperture stop S is fixed, the third lens group G3 moves toward the object side, the fourth lens group G4 moves once toward the image side, and then moves toward the object side, and the fifth lens group G5 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L113 in the first lens group G1, both surfaces of the biconcave lens L121 in the second lens group G2, a surface on the object side of the biconvex lens L131 and a surface on the image side of the biconcave lens L132 in the third lens group G3, a surface on the image side of the positive meniscus lens L142 having the convex surface directed toward the object side in the fourth lens group G4, and a surface on the object side of the biconvex lens L151 in the fifth lens group G5.

Next, numerical data of the eighth embodiment will be enumerated.

Numerical data 8 r1 = 23.417 d1 = 1 Nd1 = 1.8061 νd1 = 40.92 r2 = 8.991 d2 = 3.7 r3 = ∞ d3 = 12 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.3 r5 = 42.756 d5 = 3.54 Nd5 = 1.741 νd5 = 52.64 (Aspheric surface) r6 = −23.653 d6 = D6 r7 = −62.454 d7 = 0.8 Nd7 = 1.8061 νd7 = 40.92 (Aspheric surface) r8 = 6.820 d8 = 0.7 (Aspheric surface) r9 = 9.53 d9 = 2.2 Nd9 = 1.7552 νd9 = 27.51 r10 = 216.48 d10 = D10 r11 = Aperture stop d11 = D11 r12 = 7.667 d12 = 6.33 Nd12 = 1.6935 νd12 = 53.21 (Aspheric surface) r13 = −11.715 d13 = 0.7 Nd13 = 1.84666 νd13 = 23.78 r14 = 28.801 d14 = D14 (Aspheric surface) r15 = 16.547 d15 = 0.6 Nd15 = 1.48749 νd15 = 70.23 r16 = 8.396 d16 = 0.1 Nd16 = 1.9712 νd16 = 12.88 r17 = 8.453 d17 = D17 (Aspheric surface) r18 = 12.298 d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34 (Aspheric surface) r19 = −1666.051 d19 = D19 r20 = ∞ d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84 r21 = ∞ d21 = 0.8 r22 = ∞ d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14 r23 = ∞ d23 = D23 Aspherical coefficients  5th surface k = 0 A4 = 1.97863E−05 A6 = 1.99130E−07 A8 = 0  7th surface k = 0 A4 = −2.76063E−04 A6 = 1.66842E−05 A8 = −1.87307E−07  8th surface k = 0 A4 = −6.00048E−04 A6 = 1.66821E−05 A8 = −1.83573E−07 12th surface k = 0 A4 = 6.73087E−05 A6 = 1.83455E−06 A8 = 1.35252E−08 14th surface k = 0 A4 = 7.20573E−04 A6 = 1.11057E−05 A8 = 9.05706E−07 17th surface k = 0 A4 = −7.32245E−06 A6 = 3.35000E−07 A8 = 0.00000E+00 18th surface k = 0 A4 = −5.22378E−05 A6 = 8.59323E−06 A8 = −1.53966E−07 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.1 13.42 17.995 FNO. 3.41 5.12 6.49 D6 3.39 9.88 10.83 D10 13.35 2.4 0.93 D11 6.12 3.14 0.4 D14 1.47 11.6 14.69 D17 1.34 2.07 3.38 D19 4.75 1.33 0.4 D23 1.37 1.37 1.37

Ninth Embodiment

FIG. 17 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a ninth embodiment of the present invention.

FIG. 18A, FIG. 18B, and FIG. 18C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the ninth embodiment, where, FIG. 18A shows the state at the wide angle end, FIG. 18B shows the intermediate state, and FIG. 18C shows the state at the telephoto end.

The zoom lens of the ninth embodiment, as shown in FIG. 17, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has positive refracting power as a whole.

The second lens group G2 includes a biconcave lens L121 and a positive meniscus lens L122 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a biconvex lens L131 and a biconcave lens L132, and has a positive refracting power as a whole.

The fourth lens group G4 includes a cemented lens which is formed by a negative meniscus lens L141 having a convex surface directed toward the object side and a negative meniscus lens L142 having a convex surface directed toward the object side, and has a negative refracting power as a whole. The negative meniscus lens L142 having the convex surface directed toward the object side is a lens having a thin center-thickness.

The fifth lens group G5 includes a positive meniscus lens L151 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward an image side, the aperture stop S is fixed, the third lens group G3 moves toward the object side, the fourth lens group G4 moves once toward the image side, and then moves toward the object side, and the fifth lens group G5 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L113 in the first lens group G1, both surfaces of the biconcave lens L121 in the second lens group G2, a surface on the object side of the biconvex lens L131 and a surface on the image side of the biconcave lens L132 in the third lens group G3, a surface on the image side of the negative meniscus lens L142 having the convex surface directed toward the object side in the fourth lens group G4, and a surface on the object side of the positive meniscus lens L151 having the convex surface directed toward the object side in the fifth lens group G5.

Next, numerical data of the ninth embodiment will be enumerated.

Numerical data 9 r1 = 23.178 d1 = 1 Nd1 = 1.8061 νd1 = 40.92 r2 = 8.968 d2 = 3.67 r3 = ∞ d3 = 12 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.3 r5 = 42.366 d5 = 3.54 Nd5 = 1.741 νd5 = 52.64 (Aspheric surface) r6 = −23.47 d6 = D6 r7 = −66.184 d7 = 0.8 Nd7 = 1.8061 νd7 = 40.92 (Aspheric surface) r8 = 6.725 d8 = 0.7 (Aspheric surface) r9 = 9.362 d9 = 2.2 Nd9 = 1.7552 νd9 = 27.51 r10 = 168.719 d10 = D10 r11 = Aperture stop d11 = D11 r12 = 7.677 d12 = 6.32 Nd12 = 1.6935 νd12 = 53.21 (Aspheric surface) r13 = −11.657 d13 = 0.7 Nd13 = 1.84666 νd13 = 23.78 r14 = 28.815 d14 = D14 (Aspheric surface) r15 = 16.437 d15 = 0.6 Nd15 = 1.48749 νd15 = 70.23 r16 = 8.459 d16 = 0.1 Nd16 = 2.0512 νd16 = 6.28 r17 = 8.423 d17 = D17 (Aspheric surface) r18 = 11.783 d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34 (Aspheric surface) r19 = 490.283 d19 = D19 r20 = ∞ d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84 r21 = ∞ d21 = 0.8 r22 = ∞ d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14 r23 = ∞ d23 = D23 Aspherical coefficients  5th surface k = 0 A4 = 1.89496E−05 A6 = 1.97953E−07 A8 = 0  7th surface k = 0 A4 = −2.76791E−04 A6 = 1.68717E−05 A8 = −1.97472E−07  8th surface k = 0 A4 = −6.09891E−04 A6 = 1.70615E−05 A8 = −2.17636E−07 12th surface k = 0 A4 = 6.94450E−05 A6 = 1.97650E−06 A8 = 1.24007E−08 14th surface k = 0 A4 = 7.23654E−04 A6 = 1.11472E−05 A8 = 9.36169E−07 17th surface k = 0 A4 = −2.39579E−05 A6 = −3.59629E−09 A8 = 0.00000E+00 18th surface k = 0 A4 = −7.13942E−05 A6 = 8.39629E−06 A8 = −1.49327E−07 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.1 13.42 17.994 FNO. 3.36 5.08 6.45 D6 3.34 9.92 10.92 D10 12.91 2.49 1.12 D11 6.71 3.27 0.4 D14 1.48 11.56 14.61 D17 1.34 2.06 3.36 D19 4.75 1.34 0.42 D23 1.37 1.37 1.37

Tenth Embodiment

FIG. 19 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a tenth embodiment of the present invention.

FIG. 20A, FIG. 20B, and FIG. 20C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the tenth embodiment, where, FIG. 20A shows the state at the wide angle end, FIG. 20B shows the intermediate state, and FIG. 20C shows the state at the telephoto end.

The zoom lens of the tenth embodiment, as shown in FIG. 19, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group G4. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L211 having a convex surface directed toward the object side, a prism L212, and a cemented lens which is formed by a biconvex lens L213 and a biconcave lens L214, and has a negative refracting power as a whole.

The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward an image side, and has a positive refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a negative meniscus lens L231 having a concave surface directed toward the object side and a positive meniscus lens L232 having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L232 having the concave surface directed toward the object side is a lens having a thin center-thickness.

The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward the object side, the aperture stop S is fixed, the third lens group G3 moves toward the image side, and the fourth lens group G4 moves toward the image side.

An aspheric surface is provided on a surface on the object side of the biconvex lens L213 in the first lens group G1, a surface on the object side of the biconvex lens L221 in the second lens group G2, a surface on the image side of the positive meniscus lens L232 having the concave surface directed toward the object side in the third lens group G3, and a surface on the object side of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of the tenth embodiment will be enumerated.

Numerical data 10 r1 = 56.802 d1 = 1.1 Nd1 = 1.7432 νd1 = 49.34 r2 = 12.142 d2 = 3 r3 = ∞ d3 = 12.5 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.4 r5 = 51.889 d5 = 2.2 Nd5 = 1.883 νd5 = 40.76 (Aspheric surface) r6 = −23.711 d6 = 0.7 Nd6 = 1.48749 νd6 = 70.23 r7 = 13.043 d7 = D7 r8 = 13.679 d8 = 3.5 Nd8 = 1.7432 νd8 = 49.34 (Aspheric surface) r9 = −12.5 d9 = 0.7 Nd9 = 1.84666 νd9 = 23.78 r10 = −53.854 d10 = D10 r11 = Aperture stop d11 = D11 r12 = −10.539 d12 = 0.7 Nd12 = 1.497 νd12 = 81.54 r13 = −100 d13 = 0.35 Nd13 = 1.41244 νd13 = 12.42 r14 = −67.682 d14 = D14 (Aspheric surface) r15 = 9.594 d15 = 3.5 Nd15 = 1.6935 νd15 = 53.21 (Aspheric surface)P r16 = −7.5 d16 = 0.7 Nd16 = 1.84666 νd16 = 23.78 r17 = −20.609 d17 = D17 r18 = ∞ d18 = 1.44 Nd18 = 1.54771 νd18 = 62.84 r19 = ∞ d19 = 0.8 r20 = ∞ d20 = 0.6 Nd20 = 1.51633 νd20 = 64.14 r21 = ∞ d21 = D21 Aspherical coefficients  5th surface k = 0 A4 = 4.20147E−05 A6 = 6.55603E−08 A8 = 0  8th surface k = 0 A4 = −3.41746E−05 A6 = −9.86817E−08 A8 = 0.00000E+00 14th surface k = 0 A4 = −4.00540E−04 A6 = 3.88317E−06 A8 = 0.00000E+00 15th surface k = 0 A4 = −2.83779E−04 A6 = 7.02894E−07 A8 = 0.00000E+00 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.008 13.7 17.997 FNO. 2.84 3.39 3.74 D7 13.77 4.96 0.8 D10 1.6 10.41 14.57 D11 1.4 7.75 9.83 D14 7.48 4.76 3 D17 5.16 1.53 1.21 D21 1.36 1.36 1.36

Eleventh Embodiment

FIG. 21 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to an eleventh embodiment of the present invention.

FIG. 22A, FIG. 22B, and FIG. 22C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the eleventh embodiment, where, FIG. 22A shows the state at the wide angle end, FIG. 22B shows the intermediate state, and FIG. 22C shows the state at the telephoto end.

The zoom lens of the eleventh embodiment, as shown in FIG. 21, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group G4. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L211 having a convex surface directed toward the object side, a prism L212, and a cemented lens which is formed by a biconvex lens L213 and a biconcave lens L214, and has a negative refracting power as a whole.

The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward an image side, and has a positive refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a negative meniscus lens L231 having a concave surface directed toward the object side and a positive meniscus lens L232 having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L232 having the concave surface directed toward the object side is a lens having a thin center-thickness.

The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward the object side, the aperture stop S is fixed, the third lens group G3 moves toward the image side, and the fourth lens group G4 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L213 in the first lens group G1, a surface on the object side of the biconvex lens L221 in the second lens group G2, a surface on the image side of the positive meniscus lens L232 having the concave surface directed toward the object side in the third lens group G3, and a surface on the object side of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of the eleventh embodiment will be enumerated.

Numerical data 11 r1 = 43.615 d1 = 1.1 Nd1 = 1.7432 νd1 = 49.34 r2 = 11.601 d2 = 3 r3 = ∞ d3 = 12.5 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.4 r5 = 64.688 d5 = 2.2 Nd5 = 1.883 νd5 = 40.76 (Aspheric surface) r6 = −24.638 d6 = 0.7 Nd6 = 1.48749 νd6 = 70.23 r7 = 13.439 d7 = D7 r8 = 13.774 d8 = 3.5 Nd8 = 1.7432 νd8 = 49.34 (Aspheric surface) r9 = −12.5 d9 = 0.7 Nd9 = 1.84666 νd9 = 23.78 r10 = −45.417 d10 = D10 r11 = Aperture stop d11 = D11 r12 = −10.952 d12 = 0.7 Nd12 = 1.51742 νd12 = 52.43 r13 = −100 d13 = 0.35 Nd13 = 1.42001 νd13 = 6.55 r14 = −69.416 d14 = D14 (Aspheric surface) r15 = 9.645 d15 = 3.5 Nd15 = 1.6935 νd15 = 53.21 (Aspheric surface) r16 = −7.5 d16 = 0.7 Nd16 = 1.84666 νd16 = 23.78 r17 = −21.038 d17 = D17 r18 = ∞ d18 = 1.44 Nd18 = 1.54771 νd18 = 62.84 r19 = ∞ d19 = 0.8 r20 = ∞ d20 = 0.6 Nd20 = 1.51633 νd20 = 64.14 r21 = ∞ d21 = D21 Aspherical coefficients  5th surface k = 0 A4 = 4.60698E−05 A6 = 9.96036E−08 A8 = 0  8th surface k = 0 A4 = −3.87866E−05 A6 = −1.30998E−07 A8 = 0.00000E+00 14th surface k = 0 A4 = −3.63317E−04 A6 = 3.83985E−06 A8 = 0.00000E+00 15th surface k = 0 A4 = −2.69565E−04 A6 = 6.89565E−07 A8 = 0.00000E+00 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.009 13.7 17.996 FNO. 2.84 3.39 3.74 D7 13.51 4.85 0.8 D10 1.6 10.27 14.31 D11 1.4 7.36 9.91 D14 7.63 5.52 3 D17 5.08 1.51 1.22 D21 1.36 1.36 1.36

Twelfth Embodiment

FIG. 23 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twelfth embodiment of the present invention;

FIG. 24A, FIG. 24B, and FIG. 24C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twelfth embodiment, where, FIG. 24A shows the state at the wide angle end, FIG. 24B shows the intermediate state, and FIG. 24C shows the state at the telephoto end.

The zoom lens of the twelfth embodiment, as shown in FIG. 23, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group G4. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L211 having a convex surface directed toward the object side, a prism L212, and a cemented lens which is formed by a biconvex lens L213 and a biconcave lens L214, and has a negative refracting power as a whole.

The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward an image side, and has a positive refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a negative meniscus lens L231 having a concave surface directed toward the object side and a positive meniscus lens L232 having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L232 having the concave surface directed toward the object side is a lens having a thin center-thickness.

The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward the object side, the aperture stop S is fixed, the third lens group G3 moves toward the image side, and the fourth lens group G4 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L213 in the first lens group G1, a surface on the object side of the biconvex lens L221 in the second lens group G2, a surface on the image side of the positive meniscus lens L232 having the concave surface directed toward the object side in the third lens group G3, and a surface on the object side of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of the twelfth embodiment will be enumerated.

Numerical data 12 r1 = 38.631 d1 = 1.1 Nd1 = 1.7432 νd1 = 49.34 r2 = 10.786 d2 = 3 r3 = ∞ d3 = 12.5 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.4 r5 = 86.106 d5 = 2.2 Nd5 = 1.883 νd5 = 40.76 (Aspheric surface) r6 = −17.571 d6 = 0.7 Nd6 = 1.48749 νd6 = 70.23 r7 = 14.621 d7 = D7 r8 = 14.647 d8 = 3.5 Nd8 = 1.7432 νd8 = 49.34 (Aspheric surface) r9 = −12.5 d9 = 0.7 Nd9 = 1.84666 νd9 = 23.78 r10 = −50.724 d10 = D10 r11 = Aperture stop d11 = D11 r12 = −9.942 d12 = 0.7 Nd12 = 1.51742 νd12 = 52.43 r13 = −100 d13 = 0.35 Nd13 = 1.51824 νd13 = 12.85 r14 = −44.550 d14 = D14 (Aspheric surface) r15 = 10.032 d15 = 3.5 Nd15 = 1.6935 νd15 = 53.21 (Aspheric surface) r16 = −7.5 d16 = 0.7 Nd16 = 1.84666 νd16 = 23.78 r17 = −18.975 d17 = D17 r18 = ∞ d18 = 1.44 Nd18 = 1.54771 νd18 = 62.84 r19 = ∞ d19 = 0.8 r20 = ∞ d20 = 0.6 Nd20 = 1.51633 νd20 = 64.14 r21 = ∞ d21 = D21 Aspherical coefficients  5th surface k = 0 A4 = 2.98434E−05 A6 = 1.16572E−07 A8 = 0  8th surface k = 0 A4 = −2.05087E−05 A6 = −8.85285E−08 A8 = 0.00000E+00 14th surface k = 0 A4 = −2.99506E−04 A6 = 1.74480E−06 A8 = 0.00000E+00 15th surface k = 0 A4 = −2.71606E−04 A6 = 6.39734E−07 A8 = 0.00000E+00 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.003 13.7 17.998 FNO. 2.84 3.39 3.74 D7 13.89 4.41 0.8 D10 1.6 11.08 14.69 D11 1.4 7.45 10.02 D14 7.29 4.65 3 D17 5.52 2.11 1.2 D21 1.36 1.36 1.36

Thirteenth Embodiment

FIG. 25 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirteenth embodiment of the present invention.

FIG. 26A, FIG. 26B, and FIG. 26C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirteenth embodiment, where, FIG. 26A shows the state at the wide angle end, FIG. 26B shows the intermediate state, and FIG. 26C shows the state at the telephoto end.

The zoom lens of the thirteenth embodiment, as shown in FIG. 25, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group G4. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L211 having a convex surface directed toward the object side, a prism L212, and a cemented lens which is formed by a biconvex lens L213 and a biconcave lens L214, and has a negative refracting power as a whole.

The second lens group G2 includes a cemented lens which his formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward an image side, and has a positive refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a negative meniscus lens L231 having a concave surface directed toward the object side and a positive meniscus lens L232 having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L232 having the concave surface directed toward the object side is a lens having a thin center-thickness.

The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward the object side, the aperture stop S is fixed, the third lens group G3 moves toward the image side, and the fourth lens group G4 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L213 in the first lens group G1, a surface on the object side of the biconvex lens L221 in the second lens group G2, a surface on the image side of the positive meniscus lens L232 having the concave surface directed toward the object side in the third lens group G3, and a surface on the object side of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of the thirteenth embodiment will be enumerated.

Numerical data 13 r1 = 52.902 d1 = 1.1 Nd1 = 1.7432 νd1 = 49.34 r2 = 11.839 d2 = 3 r3 = ∞ d3 = 12.5 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.4 r5 = 59.484 d5 = 2.2 Nd5 = 1.883 νd5 = 40.76 (Aspheric surface) r6 = −20.338 d6 = 0.7 Nd6 = 1.48749 νd6 = 70.23 r7 = 13.453 d7 = D7 r8 = 13.734 d8 = 3.5 Nd8 = 1.7432 νd8 = 49.34 (Aspheric surface) r9 = −12.5 d9 = 0.7 Nd9 = 1.84666 νd9 = 23.78 r10 = −55.341 d10 = D10 r11 = Aperture stop d11 = D11 r12 = −8.56 d12 = 0.7 Nd12 = 1.51742 νd12 = 52.43 r13 = −29.5 d13 = 0.35 Nd13 = 1.54856 νd13 = 7.04 r14 = −26.550 d14 = D14 (Aspheric surface) r15 = 10.993 d15 = 3.5 Nd15 = 1.6935 νd15 = 53.21 (Aspheric surface) r16 = −7.2 d16 = 0.7 Nd16 = 1.84666 νd16 = 23.78 r17 = −16.267 d17 = D17 r18 = ∞ d18 = 1.44 Nd18 = 1.54771 νd18 = 62.84 r19 = ∞ d19 = 0.8 r20 = ∞ d20 = 0.6 Nd20 = 1.51633 νd20 = 64.14 r21 = ∞ d21 = D21 Aspherical coefficients  5th surface k = 0 A4 = 2.68146E−05 A6 = 1.18119E−07 A8 = 0.00000E+00  8th surface k = 0 A4 = −2.10592E−05 A6 = −1.09460E−07 A8 = −4.21441E−07 14th surface k = 0 A4 = −3.39397E−04 A6 = 2.16289E−06 A8 = −1.28129E−06 15th surface k = 0 A4 = −2.85478E−04 A6 = 5.83204E−07 A8 = 5.27383E−08 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 5.998 13.698 17.988 FNO. 2.84 3.4 3.75 D7 13.81 3.92 0.8 D10 1.6 11.5 14.62 D11 1.41 6.05 9.15 D14 6.49 4.93 3 D17 5.45 2.37 1.2 D21 1.36 1.36 1.36

Fourteenth Embodiment

FIG. 27 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a fourteenth embodiment of the present invention.

FIG. 28A, FIG. 28B, and FIG. 28C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the fourteenth embodiment, where, FIG. 28A shows the state at the wide angle end, FIG. 28B shows the intermediate state, and FIG. 28C shows the state at the telephoto end.

The zoom lens of the fourteenth embodiment, as shown in FIG. 27, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group G4. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L211 having a convex surface directed toward the object side, a prism L212, and a cemented lens which is formed by a biconvex lens L213 and a biconcave lens L214, and has a negative refracting power as a whole.

The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward an image side, and has a positive refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a negative meniscus lens L231 having a concave surface directed toward the object side and a positive meniscus lens L232 having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L232 having the concave surface directed toward the object side is a lens having a thin center-thickness.

The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward the object side, the aperture stop S is fixed, the third lens group G3 moves toward the image side, and the fourth lens group G4 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L213 in the first lens group G1, a surface on the object side of the biconvex lens L221 in the second lens group G2, a surface on the image side of the positive meniscus lens L232 having the concave surface directed toward the object side in the third lens group G3, and a surface on the object side of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of the fourteenth embodiment will be enumerated.

Numerical data 14 r1 = 38.891 d1 = 1.1 Nd1 = 1.7432 νd1 = 49.34 r2 = 9.835 d2 = 3 r3 = ∞ d3 = 12.5 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.4 r5 = 60.054 d5 = 2.2 Nd5 = 1.883 νd5 = 40.76 (Aspheric surface) r6 = −24.469 d6 = 0.7 Nd6 = 1.48749 νd6 = 70.23 r7 = 12.862 d7 = D7 r8 = 15.353 d8 = 3.5 Nd8 = 1.7432 νd8 = 49.34 (Aspheric surface) r9 = −12.5 d9 = 0.7 Nd9 = 1.84666 νd9 = 23.78 r10 = −39.902 d10 = D10 r11 = Aperture stop d11 = D11 r12 = −9.98 d12 = 0.7 Nd12 = 1.51729 νd12 = 65.94 r13 = −100 d13 = 0.35 Nd13 = 1.65228 νd13 = 12.75 r14 = −48.119 d14 = D14 (Aspheric surface) r15 = 11.111 d15 = 3.5 Nd15 = 1.6935 νd15 = 53.21 (Aspheric surface) r16 = −7.5 d16 = 0.7 Nd16 = 1.84666 νd16 = 23.78 r17 = −22.56 d17 = D17 r18 = ∞ d18 = 1.44 Nd18 = 1.54771 νd18 = 62.84 r19 = ∞ d19 = 0.8 r20 = ∞ d20 = 0.6 Nd20 = 1.51633 νd20 = 64.14 r21 = ∞ d21 = D21 Aspherical coefficients  5th surface k = 0 A4 = 7.13925E−05 A6 = 1.71754E−07 A8 = 0  8th surface k = 0 A4 = −3.78743E−05 A6 = −1.60871E−07 A8 = 0.00000E+00 14th surface k = 0 A4 = −4.07707E−04 A6 = 2.30478E−06 A8 = 0.00000E+00 15th surface k = 0 A4 = −3.45182E−04 A6 = 2.31185E−06 A8 = 0.00000E+00 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.101 10.553 17.994 FNO. 3.06 3.65 5.17 D7 17.7 5.59 1.05 D10 5.85 9.39 13.35 D11 0.65 4.63 15.8 D14 5.72 3.86 2.69 D17 5.77 6.71 5.32 D21 1.36 1.36 1.36

Fifteenth Embodiment

FIG. 29 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a fifteenth embodiment of the present invention.

FIG. 30A, FIG. 30B, and FIG. 30C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the fifteenth embodiment, where, FIG. 30A shows the state at the wide angle end, FIG. 30B shows the intermediate state, and FIG. 30C shows the state at the telephoto end.

The zoom lens of the fifteenth embodiment, as shown in FIG. 29, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group G4. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L211 having a convex surface directed toward the object side, a prism L212, and a cemented lens which is formed by a biconvex lens L213 and a biconcave lens L214, and has a negative refracting power as a whole.

The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward an image side, and has a positive refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a negative meniscus lens L231 having a concave surface directed toward the object side and a positive meniscus lens L232 having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L232 having the concave surface directed toward the object side is a lens having a thin center-thickness.

The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward the object side, the aperture stop S is fixed, the third lens group G3 moves toward the image side, and the fourth lens group G4 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L213 in the first lens group G1, a surface on the object side of the biconvex lens L221 in the second lens group G2, a surface on the image side of the positive meniscus lens L232 having the concave surface directed toward the object side in the third lens group G3, and a surface on the object side of the biconvex lens L241 in the fourth lens group G241.

Next, numerical data of the fifteenth embodiment will be enumerated.

Numerical data 15 r1 = 57.868 d1 = 1.1 Nd1 = 1.7432 νd1 = 49.34 r2 = 11.248 d2 = 3.05 r3 = ∞ d3 = 12.5 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.4 r5 = 51.247 d5 = 3.42 Nd5 = 1.883 νd5 = 40.76 (Aspheric surface) r6 = −24.561 d6 = 0.9 Nd6 = 1.48749 νd6 = 70.23 r7 = 12.542 d7 = D7 r8 = 14.337 d8 = 7.69 Nd8 = 1.7432 νd8 = 49.34 (Aspheric surface) r9 = −12.5 d9 = 3.98 Nd9 = 1.84666 νd9 = 23.78 r10 = −50.883 d10 = D10 r11 = Aperture stop d11 = D11 r12 = −10.713 d12 = 0.9 Nd12 = 1.52852 νd12 = 58.86 r13 = −100 d13 = 0.35 Nd13 = 1.59885 νd13 = 6.52 r14 = −63.005 d14 = D14 (Aspheric surface) r15 = 9.560 d15 = 4.34 Nd15 = 1.71237 νd15 = 44.16 (Aspheric surface) r16 = −7.5 d16 = 3.5 Nd16 = 1.81657 νd16 = 21.77 r17 = −48.273 d17 = D17 r18 = ∞ d18 = 1.44 Nd18 = 1.54771 νd18 = 62.84 r19 = ∞ d19 = 0.8 r20 = ∞ d20 = 0.6 Nd20 = 1.51633 νd20 = 64.14 r21 = ∞ d21 = D21 Aspherical coefficients  5th surface k = 0 A4 = 6.06374E−05 A6 = 2.96748E−08 A8 = 0  8th surface k = 0 A4 = −3.79953E−05 A6 = −9.01187E−08 A8 = 0.00000E+00 14th surface k = 0 A4 = −4.27739E−04 A6 = 3.55154E−06 A8 = 0.00000E+00 15th surface k = 0 A4 = −3.08817E−04 A6 = 1.61244E−06 A8 = 0.00000E+00 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.101 10.555 17.998 FNO. 3.24 3.5 4.82 D7 18.49 5.99 1.21 D10 0.91 7.03 11.89 D11 0.61 2.38 11.94 D14 6.75 5.1 4.34 D17 4.75 5.22 3.4 D21 1.36 1.36 1.36

Sixteenth Embodiment

FIG. 31 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a sixteenth embodiment of the present invention.

FIG. 32A, FIG. 32B, and FIG. 32C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the sixteenth embodiment, where, FIG. 32A shows the state at the wide angle end, FIG. 32B shows the intermediate state, and FIG. 32C shows the state at the telephoto end.

The zoom lens of the sixteenth embodiment, as shown in FIG. 31, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group G4. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L211 having a convex surface directed toward the object side, a prism L212, and a cemented lens which is formed by a biconvex lens L213 and a biconcave lens L214, and has a negative refracting power as a whole.

The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward an image side, and has a positive refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a negative meniscus lens L231 having a concave surface directed toward the object side and a positive meniscus lens L232 having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L232 having the concave surface directed toward the object side is a lens having a thin center-thickness.

The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward the object side, the third lens group G3 moves toward the image side, and the fourth lens group G4 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L213 in the first lens group G1, a surface on the object side of the biconvex lens L221 in the second lens group G2, a surface on the image side of the positive meniscus lens L232 having the concave surface directed toward the object side in the third lens group G3, and a surface on the object side of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of the sixteenth embodiment will be enumerated.

Numerical data 16 r1 = 62.959 d1 = 1.1 Nd1 = 1.7432 νd1 = 49.34 r2 = 11.433 d2 = 2.98 r3 = ∞ d3 = 12.5 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.4 r5 = 50.756 d5 = 2.79 Nd5 = 1.883 νd5 = 40.76 (Aspheric surface) r6 = −24.668 d6 = 0.9 Nd6 = 1.48749 νd6 = 70.23 r7 = 12.505 d7 = D7 r8 = 14.492 d8 = 7.39 Nd8 = 1.7432 νd8 = 49.34 (Aspheric surface) r9 = −12.5 d9 = 5.86 Nd9 = 1.84666 νd9 = 23.78 r10 = −48.836 d10 = D10 r11 = Aperture stop d11 = D11 r12 = −9.553 d12 = 0.9 Nd12 = 1.53585 νd12 = 55.13 r13 = −100 d13 = 0.35 Nd13 = 1.79525 νd13 = 9.95 r14 = −44.152 d14 = D14 (Aspheric surface) r15 = 9.226 d15 = 4.3 Nd15 = 1.70794 νd15 = 47.46 (Aspheric surface) r16 = −7.5 d16 = 3.48 Nd16 = 1.82618 νd16 = 21.48 r17 = −49.212 d17 = D17 r18 = ∞ d18 = 1.44 Nd18 = 1.54771 νd18 = 62.84 r19 = ∞ d19 = 0.8 r20 = ∞ d20 = 0.6 Nd20 = 1.51633 νd20 = 64.14 r21 = ∞ d21 = D21 Aspherical coefficients 5th surface k = 0 A4 = 6.09647E−05 A6 = 1.57459E−08 A8 = 0 8th surface k = 0 A4 = −3.80323E−05 A6 = −6.55996E−08 A8 = 0.00000E+00 14th surface k = 0 A4 = −4.26592E−04 A6 = 4.19255E−06 A8 = 0.00000E+00 15th surface k = 0 A4 = −3.87754E−04 A6 = 2.28630E−06 A8 = 0.00000E+00 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.1 10.553 17.995 FNO. 3.19 3.47 4.77 D7 18.27 5.85 1.19 D10 0.7 6.91 12.07 D11 0.64 2.49 12.19 D14 5.78 4.42 3.89 D17 4.69 5.18 3.29 D21 1.36 1.36 1.36

Seventeenth Embodiment

FIG. 33 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a seventeenth embodiment of the present invention.

FIG. 34A, FIG. 34B, and FIG. 34C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the seventeenth embodiment, where, FIG. 34A shows the state at the wide angle end, FIG. 34B shows the intermediate state, and FIG. 34C shows the state at the telephoto end.

The zoom lens of the seventeenth embodiment, as shown in FIG. 33, has in order form an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group G4. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L211 having a convex surface directed toward the object side, a prism L212, and a cemented lens which is formed by a biconvex lens L213 and a biconcave lens L213, and has a negative refracting power as a whole.

The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward an image side, and has a positive refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a negative meniscus lens L231 having a concave surface directed toward the object side and a positive meniscus lens L232 having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L232 having the concave surface directed toward the object side is a lens having a thin center-thickness.

The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward the object side, the aperture stop S is fixed, the third lens group G3 moves toward the image side, and the fourth lens group G4 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L213 in the first lens group, a surface on the object side of the biconvex lens L221 in the second lens group G2, a surface on the image side of the positive meniscus lens L232 having the concave surface directed toward the object side in the third lens group G3, and a surface on the object side of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of the seventeenth embodiment will be enumerated.

Numerical data 17 r1 = 68.079 d1 = 1.1 Nd1 = 1.7432 νd1 = 49.34 r2 = 11.633 d2 = 2.99 r3 = ∞ d3 = 12.5 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.4 r5 = 50.301 d5 = 2.33 Nd5 = 1.883 νd5 = 40.76 (Aspheric surface) r6 = −24.516 d6 = 0.9 Nd6 = 1.48749 νd6 = 70.23 r7 = 12.478 d7 = D7 r8 = 14.504 d8 = 7.39 Nd8 = 1.7432 νd8 = 49.34 (Aspheric surface) r9 = −12.5 d9 = 6.85 Nd9 = 1.84666 νd9 = 23.78 r10 = −48.451 d10 = D10 r11 = Aperture d11 = D11 stop r12 = −8.927 d12 = 0.9 Nd12 = 1.53859 νd12 = 53.87 r13 = −100 d13 = 0.35 Nd13 = 1.9712 νd13 = 12.88 r14 = −38.346 d14 = D14 (Aspheric surface) r15 = 8.915 d15 = 4.15 Nd15 = 1.70159 νd15 = 48.9 (Aspheric surface) r16 = −7.5 d16 = 3 Nd16 = 1.8402 νd16 = 21.32 r17 = −47.582 d17 = D17 r18 = ∞ d18 = 1.44 Nd18 = 1.54771 νd18 = 62.84 r19 = ∞ d19 = 0.8 r20 = ∞ d20 = 0.6 Nd20 = 1.51633 νd20 = 64.14 r21 = ∞ d21 = D21 Aspherical coefficients 5th surface k = 0 A4 = 5.92982E−05 A6 = 5.24010E−09 A8 = 0 8th surface k = 0 A4 = −3.76559E−05 A6 = −4.70537E−08 A8 = 0.00000E+00 14th surface k = 0 A4 = −4.04099E−04 A6 = 4.26752E−06 A8 = 0.00000E+00 15th surface k = 0 A4 = −4.50778E−04 A6 = 2.93020E−06 A8 = 0.00000E+00 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.1 10.553 17.997 FNO. 3.12 3.41 4.64 D7 17.78 5.7 1.23 D10 0.56 6.93 12.47 D11 0.67 2.77 12.22 D14 5.2 3.94 3.41 D17 4.67 4.99 2.88 D21 1.36 1.36 1.36

Eighteenth Embodiment

FIG. 35 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to an eighteenth embodiment of the present invention.

FIG. 36A, FIG. 36B, and FIG. 36C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the eighteenth embodiment, where, FIG. 36A shows the state at the wide angle end, FIG. 36B shows the intermediate state, and FIG. 36C shows the state at the telephoto end.

The zoom lens of the eighteenth embodiment, as shown in FIG. 35, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group G4. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L211 having a convex surface directed toward the object side, a prism L212, and a cemented lens which is formed by a biconvex lens L213 and a biconcave lens L214, and has a negative refracting power as a whole.

The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward an image side, and has a positive refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a negative meniscus lens L231 having a concave surface directed toward the object side and a positive meniscus lens L232 having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L232 having the concave surface directed toward the object side is a lens having a thin center-thickness.

The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward the object side, the aperture stop S is fixed, the third lens group G3 moves toward the image side, and the fourth lens group G4 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L213 in the first lens group G1, a surface on the object side of the biconvex lens L221 in the second lens group G2, a surface on the image side of the positive meniscus lens. L232 having the concave surface directed toward the object side in the third lens group G3, and a surface on the object side of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of the eighteenth embodiment will be enumerated.

Numerical data 18 r1 = 63.79 d1 = 1.1 Nd1 = 1.7432 νd1 = 49.34 r2 = 11.649 d2 = 3.06 r3 = ∞ d3 = 12.5 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.4 r5 = 46.980 d5 = 3.3 Nd5 = 1.883 νd5 = 40.76 (Aspheric surface) r6 = −25.318 d6 = 0.9 Nd6 = 1.48749 νd6 = 70.23 r7 = 12.314 d7 = D7 r8 = 14.146 d8 = 7.85 Nd8 = 1.7432 νd8 = 49.34 (Aspheric surface) r9 = −12.5 d9 = 4.47 Nd9 = 1.84666 νd9 = 23.78 r10 = −53.448 d10 = D10 r11 = Aperture stop d11 = D11 r12 = −9.716 d12 = 0.9 Nd12 = 1.53062 νd12 = 57.73 r13 = −100 d13 = 0.35 Nd13 = 2.0512 νd13 = 6.28 r14 = −76.868 d14 = D14 (Aspheric surface) r15 = 8.784 d15 = 4.06 Nd15 = 1.70975 νd15 = 45.62 (Aspheric surface) r16 = −7.5 d16 = 3.07 Nd16 = 1.82469 νd16 = 21.99 r17 = −41.356 d17 = D17 r18 = ∞ d18 = 1.44 Nd18 = 1.54771 νd18 = 62.84 r19 = ∞ d19 = 0.8 r20 = ∞ d20 = 0.6 Nd20 = 1.51633 νd20 = 64.14 r21 = ∞ d21 = D21 Aspherical coefficients 5th surface k = 0 A4 = 5.85091E−05 A6 = 1.63330E−08 A8 = 0 8th surface k = 0 A4 = −3.75473E−05 A6 = −8.44888E−08 A8 = 0.00000E+00 14th surface k = 0 A4 = −2.99314E−04 A6 = 3.36694E−06 A8 = 0.00000E+00 15th surface k = 0 A4 = −3.61178E−04 A6 = 1.58918E−06 A8 = 0.00000E+00 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.099 10.552 17.993 FNO. 3.03 3.33 4.5 D7 17.47 5.63 1.2 D10 1.14 7.24 12.69 D11 0.62 2.75 11.06 D14 6.52 5.15 4.63 D17 4.84 5.06 3.15 D21 1.36 1.36 1.36

Nineteenth Embodiment

FIG. 37 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a nineteenth embodiment of the present invention.

FIG. 38A, FIG. 38B, and FIG. 38C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the nineteenth embodiment of the present invention, where, FIG. 38A shows the state at the wide angle end, FIG. 38B shows the intermediate state, and FIG. 38C shows the state at the telephoto end.

The zoom lens of the nineteenth embodiment, as shown in FIG. 37, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refracting power as a whole.

The second lens group G2 includes a biconcave lens L121 and a positive meniscus lens L122 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a biconvex lens L131 and a biconcave lens L132, and has a positive refracting power as a whole.

The fourth lens group G4 includes a cemented lens which is formed by a negative meniscus lens L141 having a convex surface directed toward the object side and a positive meniscus lens L142 having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L142 having the convex surface directed toward the object side is a lens having a thin center-thickness.

The fifth lens group G5 includes a biconvex lens L151, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward an image side, the aperture stop S is fixed, the third lens group G3 moves toward the object side, the fourth lens group G4 moves once toward the image side, and then moves toward the object side, and the fifth lens group G5 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L113 in the first lens group G1, both surfaces of the biconcave lens L121 in the second lens group G2, a surface on the object side of the biconvex lens L131 and a surface on the image side of the biconcave lens L132 in the third lens group G3, a surface on the image side of the positive meniscus lens L142 having the convex surface directed toward the object side in the fourth lens group G4, and a surface on the object side of the biconvex lens L151 in the fifth lens group G5.

Next, numerical data of the nineteenth embodiment will be enumerated.

Numerical data 19 r1 = 26.33 d1 = 1 Nd1 = 1.8061 νd1 = 40.92 r2 = 10.006 d2 = 2.9 r3 = ∞ d3 = 12 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.3 r5 = 26.758 d5 = 3.54 Nd5 = 1.741 νd5 = 52.64 (Aspheric surface) r6 = −28.965 d6 = D6 r7 = −131.345 d7 = 0.8 Nd7 = 1.8061 νd7 = 40.92 (Aspheric surface) r8 = 5.919 d8 = 0.7 (Aspheric surface) r9 = 8.064 d9 = 2.2 Nd9 = 1.7552 νd9 = 27.51 r10 = 66.381 d10 = D10 r11 = Aperture stop d11 = D11 r12 = 7.833 d12 = 5.8 Nd12 = 1.6935 νd12 = 53.21 (Aspheric surface) r13 = −11.499 d13 = 0.7 Nd13 = 1.84666 νd13 = 23.78 r14 = 30.622 d14 = D14 (Aspheric surface) r15 = 40.578 d15 = 0.6 Nd15 = 1.48749 νd15 = 70.23 r16 = 10.949 d16 = 0.1 Nd16 = 1.60687 νd16 = 27.03 r17 = 12.043 d17 = D17 (Aspheric surface) r18 = 13.800 d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34 (Aspheric surface) r19 = −43.765 d19 = D19 r20 = ∞ d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84 r21 = ∞ d21 = 0.8 r22 = ∞ d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14 r23 = ∞ d23 = D23 Aspherical coefficients 5th surface k = 0 A4 = 4.05861E−06 A6 = 2.45198E−07 A8 = 0.00000E+00 7th surface k = 0 A4 = −3.70360E−04 A6 = 2.03291E−05 A8 = −5.16020E−07 8th surface k = 0 A4 = −8.18468E−04 A6 = 2.71936E−05 A8 = −1.40721E−06 12th surface k = 0 A4 = 1.26362E−04 A6 = 1.67158E−06 A8 = 5.21583E−08 14th surface k = 0 A4 = 7.68617E−04 A6 = 5.97869E−06 A8 = 9.78572E−07 17th surface k = 0 A4 = 1.49229E−04 A6 = −4.05344E−06 A8 = 0.00000E+00 18th surface k = 0 A4 = 5.20616E−05 A6 = 3.84073E−06 A8 = −1.76970E−07 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.005 13.699 17.995 FNO. 2.85 4.82 5.88 D6 0.8 6.91 8.38 D10 8.97 2.86 1.39 D11 11.32 3.77 1.19 D14 1.71 11.94 14.15 D17 1.32 2.04 3.26 D19 4.76 1.36 0.51 D23 1.36 1.37 1.36

Twentieth Embodiment

FIG. 39 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twentieth embodiment of the present invention.

FIG. 40A, FIG. 40B, and FIG. 40C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twentieth embodiment, where, FIG. 40A shows the state at the wide angle end, FIG. 40B shows the intermediate state, and FIG. 40C shows the state at the telephoto end.

The zoom lens of the twentieth embodiment, as shown in FIG. 39, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refracting power as a whole.

The second lens group G2 includes a biconcave lens L121 and a positive meniscus lens L122 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a biconvex lens L131 and a biconcave lens L132, and has a positive refracting power as a whole.

The fourth lens group G4 includes a cemented lens which is formed by a negative meniscus lens L141 having a convex surface directed toward the object side and a positive meniscus lens L142 having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L142 having the convex surface directed toward the object side is a lens having a thin center-thickness.

The fifth lens group G5 includes a biconvex lens L151, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward an image side, the aperture stop S is fixed, the third lens group G3 moves toward the object side, the fourth lens group G4 moves once toward the image side, and then moves toward the object side, and the fifth lens group G5 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L113 in the first lens group G1, both surfaces of the biconcave lens L121 in the second lens group G2, a surface on the object side of the biconvex lens L131 and a surface on the image side of the biconcave lens L132 in the third lens group G3, a surface on the image side of the positive meniscus lens L142 having the convex surface directed toward the object side in the fourth lens group G4, and a surface on the object side of the biconvex lens L151 in the fifth lens group G5.

Next, numerical data of the twentieth embodiment will be enumerated.

Numerical data 20 r1 = 30.613 d1 = 1 Nd1 = 1.8061 νd1 = 40.92 r2 = 10.004 d2 = 2.9 r3 = ∞ d3 = 12 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.3 r5 = 25.367 d5 = 3.54 Nd5 = 1.741 νd5 = 52.64 (Aspheric surface) r6 = −30.821 d6 = D6 r7 = −139.143 d7 = 0.8 Nd7 = 1.8061 νd7 = 40.92 (Aspheric surface) r8 = 6.251 d8 = 0.7 (Aspheric surface) r9 = 8.353 d9 = 2.2 Nd9 = 1.7552 νd9 = 27.51 r10 = 89.717 d10 = D10 r11 = Aperture stop d11 = D11 r12 = 8.190 d12 = 5.96 Nd12 = 1.6935 νd12 = 53.21 (Aspheric surface) r13 = −11.471 d13 = 0.7 Nd13 = 1.84666 νd13 = 23.78 r14 = 27.082 d14 = D14 (Aspheric surface) r15 = 30.851 d15 = 0.6 Nd15 = 1.48749 νd15 = 70.23 r16 = 10.858 d16 = 0.1 Nd16 = 1.60258 νd16 = 18.58 r17 = 11.942 d17 = D17 (Aspheric surface) r18 = 12.917 d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34 (Aspheric surface) r19 = −39.589 d19 = D19 r20 = ∞ d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84 r21 = ∞ d21 = 0.8 r22 = ∞ d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14 r23 = ∞ d23 = D23 Aspherical coefficients 5th surface k = 0 A4 = 1.11418E−05 A6 = 7.82363E−08 A8 = 0 7th surface k = 0 A4 = 3.05928E−06 A6 = 5.15862E−06 A8 = −1.60243E−07 8th surface k = 0 A4 = −3.11351E−04 A6 = 7.68460E−06 A8 = −6.23664E−07 12th surface k = 0 A4 = 8.68188E−05 A6 = 3.96805E−06 A8 = −9.06844E−09 14th surface k = 0 A4 = 5.70877E−04 A6 = 1.11773E−05 A8 = 6.97910E−07 17th surface k = 0 A4 = 2.53040E−04 A6 = −4.57584E−06 A8 = 0.00000E+00 18th surface k = 0 A4 = 9.09876E−05 A6 = 1.42880E−07 A8 = −2.35059E−08 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 5.998 13.7 17.982 FNO. 2.85 4.5 5.64 D6 0.8 9.32 10.33 D10 10.89 2.37 1.36 D11 11.09 4 1.16 D14 1.71 11.67 15.59 D17 2.54 2.18 2.61 D19 4.54 2.03 0.53 D23 1.36 1.36 1.36

Twenty First Embodiment

FIG. 41 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty first embodiment of the present invention.

FIG. 42A, FIG. 42B, and FIG. 42C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty first embodiment, where, FIG. 42A shows the state at the wide angle end, FIG. 42B shows the intermediate state, and FIG. 42C shows the state at the telephoto end.

The zoom lens of the twenty first embodiment, as shown in FIG. 41, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refracting power as a whole.

The second lens group G2 includes a biconcave lens L121 and a positive meniscus lens L122 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a biconvex lens L131 and a biconcave lens L132, and has a positive refracting power as a whole.

The fourth lens group G4 includes a cemented lens which is formed by a negative meniscus lens L141 having a convex surface directed toward the object side and a positive meniscus lens L142 having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L142 having the convex surface directed toward the object side is a lens having a thin center-thickness.

The fifth lens group G5 includes a biconvex lens L151, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward an image side, the aperture stop S is fixed, the third lens group G3 moves toward the object side, the fourth lens group G4 moves once toward the image side, and then moves toward the object side, and the fifth lens group G5 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L113 in the first lens group G1, both surfaces of the biconcave lens L121 in the second lens group G2, a surface on the object side of the biconvex lens L131 and a surface on the image side of the biconcave lens L132 in the third lens group G3, a surface on the image side of the positive meniscus lens L142 having the convex surface directed toward the object side in the fourth lens group G4, and a surface on the object side of the biconvex lens L151 in the fifth lens group G5.

Next, numerical data of the twenty first embodiment will be enumerated.

Numerical data 21 r1 = 26.323 d1 = 1 Nd1 = 1.8061 νd1 = 40.92 r2 = 10.008 d2 = 2.9 r3 = ∞ d3 = 12 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.3 r5 = 26.751 d5 = 3.54 Nd5 = 1.741 νd5 = 52.64 (Aspheric surface) r6 = −28.956 d6 = D6 r7 = −131.499 d7 = 0.8 Nd7 = 1.8061 νd7 = 40.92 (Aspheric surface) r8 = 5.919 d8 = 0.7 (Aspheric surface) r9 = 8.063 d9 = 2.2 Nd9 = 1.7552 νd9 = 27.51 r10 = 66.411 d10 = D10 r11 = Aperture d11 = D11 stop r12 = 7.833 d12 = 5.8 Nd12 = 1.6935 νd12 = 53.21 (Aspheric surface) r13 = −11.499 d13 = 0.7 d13 = 1.84666 νd13 = 23.78 r14 = 30.626 d14 = D14 (Aspheric surface) r15 = 40.611 d15 = 0.6 Nd15 = 1.48749 νd15 = 70.23 r16 = 10.951 d16 = 0.1 Nd16 = 1.69556 νd16 = 25.02 r17 = 12.040 d17 = D17 (Aspheric surface) r18 = 13.804 d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34 (Aspheric surface) r19 = −43.815 d19 = D19 r20 = ∞ d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84 r21 = ∞ d21 = 0.8 r22 = ∞ d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14 r23 = ∞ d23 = D23 Aspherical coefficients 5th surface k = 0 A4 = 4.79969E−06 A6 = 1.77649E−07 A8 = 0 7th surface k = 0 A4 = −3.70126E−04 A6 = 2.07943E−05 A8 = −5.46313E−07 8th surface k = 0 A4 = −8.17289E−04 A6 = 2.67093E−05 A8 = −1.44560E−06 12th surface k = 0 A4 = 1.26495E−04 A6 = 1.60044E−06 A8 = 5.40471E−08 14th surface k = 0 A4 = 7.67067E−04 A6 = 5.64377E−06 A8 = 1.00057E−06 17th surface k = 0 A4 = 1.47554E−04 A6 = −4.25967E−06 A8 = 0.00000E+00 18th surface k = 0 A4 = 5.40303E−05 A6 = 4.23811E−06 A8 = −1.98225E−07 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 5.971 13.646 17.936 FNO. 2.83 4.8 5.86 D6 0.8 6.91 8.38 D10 8.97 2.86 1.39 D11 11.32 3.77 1.19 D14 1.71 11.94 14.15 D17 1.32 2.04 3.26 D19 4.76 1.36 0.51 D23 1.28 1.3 1.28

Twenty Second Embodiment

FIG. 43 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty second embodiment of the present invention.

FIG. 44A, FIG. 44B, and FIG. 44C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty second embodiment, where, FIG. 44A shows the state at the wide angle end, FIG. 44B shows the intermediate state, and FIG. 44C shows the state at the telephoto end.

The zoom lens of the twenty second embodiment, as shown in FIG. 43, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refracting power as a whole.

The second lens group G2 includes a biconcave lens L121 and a positive meniscus lens L122 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a biconvex lens L131 and a biconcave lens L132, and has a positive refracting power as a whole.

The fourth lens group G4 includes a cemented lens which is formed by a negative meniscus lens L141 having a convex surface directed toward the object side and a positive meniscus lens L142 having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L142 having the convex surface directed toward the object side is a lens having a thin center-thickness.

The fifth lens group G5 includes a biconvex lens L151, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward an image side, the aperture stop S is fixed, the third lens group G3 moves toward the object side, the fourth lens group G4 moves once toward the image side, and then moves toward the object side, and the fifth lens group G5 moves toward the image side.

An aspheric surface is provided on a surface on the object side of the biconvex lens L113 in the first lens group G1, both surfaces of the biconcave lens L121 in the second lens group G2, a surface on the object side of the biconvex lens L131 and a surface on the image side of the biconcave lens L132 in the third lens group G3, a surface on the image side of the positive meniscus lens L142 having the convex surface directed toward the object side in the fourth lens group G4, and a surface on the object side of the biconvex lens L151 in the fifth lens group G5.

Next, numerical data of the twenty second embodiment will be enumerated.

Numerical data 22 r1 = 32.631 d1 = 1 Nd1 = 1.8061 νd1 = 40.92 r2 = 9.985 d2 = 2.9 r3 = ∞ d3 = 12 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.3 r5 = 25.505 d5 = 3.54 Nd5 = 1.741 νd5 = 52.64 (Aspheric surface) r6 = −31.527 d6 = D6 r7 = −151.509 d7 = 0.8 Nd7 = 1.8061 νd7 = 40.92 (Aspheric surface) r8 = 6.307 d8 = 0.7 (Aspheric surface) r9 = 8.373 d9 = 2.2 Nd9 = 1.7552 νd9 = 27.51 r10 = 87.071 d10 = D10 r11 = Aperture stop d11 = D11 r12 = 8.110 d12 = 6.01 Nd12 = 1.6935 νd12 = 53.21 (Aspheric surface) r13 = −11.313 d13 = 0.7 Nd13 = 1.84666 νd13 = 23.78 r14 = 26.936 d14 = D14 (Aspheric surface) r15 = 34.857 d15 = 0.6 Nd15 = 1.48749 νd15 = 70.23 r16 = 11.538 d16 = 0.1 Nd16 = 1.72568 νd16 = 18.68 r17 = 12.691 d17 = D17 (Aspheric surface) r18 = 13.654 d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34 (Aspheric surface) r19 = −43.21 d19 = D19 r20 = ∞ d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84 r21 = ∞ d21 = 0.8 r22 = ∞ d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14 r23 = ∞ d23 = D23 Aspherical coefficients  5th surface k = 0 A4 = 6.81895E−06 A6 = 1.57853E−07 A8 = 0  7th surface k = 0 A4 = −1.70993E−06 A6 = 2.36923E−06 A8 = −8.61161E−08  8th surface k = 0 A4 = −3.29439E−04 A6 = 4.30202E−06 A8 = −4.88617E−07 12th surface k = 0 A4 = 8.07503E−05 A6 = 3.66307E−06 A8 = −3.68004E−08 14th surface k = 0 A4 = 6.11551E−04 A6 = 1.35724E−05 A8 = 4.04446E−07 17th surface k = 0 A4 = 1.30946E−05 A6 = −2.52309E−06 A8 = 0.00000E+00 18th surface k = 0 A4 = −7.62235E−06 A6 = −2.71920E−07 A8 = −2.83588E−09 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.02 13.7 17.993 FNO. 2.85 4.35 5.45 D6 0.8 10.48 11.56 D10 12.16 2.48 1.4 D11 10.47 4.03 1.19 D14 1.69 11.35 15.31 D17 2.99 2.24 2.67 D19 4.54 2.06 0.5 D23 1.36 1.36 1.36

Twenty Third Embodiment

FIG. 45 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty third embodiment of the present invention.

FIG. 46A, FIG. 46B, and FIG. 46C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty third embodiment, where, FIG. 46A shows the state at the wide angle end, FIG. 46B shows the intermediate state, and FIG. 46C shows the state at the telephoto end.

The zoom lens of the twenty third embodiment, as shown in FIG. 45, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refracting power as a whole.

The second lens group G2 includes a biconcave lens L121 and a positive meniscus lens L122 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a biconvex lens L131 and a biconcave lens L132, and has a positive refracting power as a whole.

The fourth lens group G4 includes a cemented lens which is formed by a negative meniscus lens L141 having a convex surface directed toward the object side and a positive meniscus lens L142 having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L142 having the convex surface directed toward the object side is a lens having a thin center-thickness.

The fifth lens group G5 includes a biconvex lens L151, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward an image side, the aperture stop S is fixed, the third lens group G3 moves toward the object side, the fourth lens group G4 moves once toward the image side, and then moves toward the object side, and the fifth lens group G5 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L113 in the first lens group G1, both surfaces of the biconcave lens L121 in the second lens group G2, a surface on the object side of the biconvex lens L131 and a surface on the image side of the biconcave lens L132 in the third lens group G3, a surface on the image side of the positive meniscus lens L142 having the convex surface directed toward the object side in the fourth lens group G4, and a surface on the object side of the biconvex lens L151 in the fifth lens group G5.

Next, numerical data of the twenty third embodiment will be enumerated.

Numerical data 23 r1 = 34.223 d1 = 1 Nd1 = 1.8061 νd1 = 40.92 r2 = 9.992 d2 = 2.9 r3 = ∞ d3 = 12 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.3 r5 = 25.219 d5 = 3.54 Nd5 = 1.741 νd5 = 52.64 (Aspheric surface) r6 = −31.093 d6 = D6 r7 = −171.219 d7 = 0.8 Nd7 = 1.8061 νd7 = 40.92 (Aspheric surface) r8 = 6.240 d8 = 0.7 (Aspheric surface) r9 = 8.367 d9 = 2.2 Nd9 = 1.7552 νd9 = 27.51 r10 = 94.233 d10 = D10 r11 = Aperture stop d11 = D11 r12 = 8.110 d12 = 6.14 Nd12 = 1.6935 νd12 = 53.21 (Aspheric surface) r13 = −10.501 d13 = 0.7 Nd13 = 1.84666 νd13 = 23.78 r14 = 27.402 d14 = D14 (Aspheric surface) r15 = 35.798 d15 = 0.6 Nd15 = 1.48749 νd15 = 70.23 r16 = 11.909 d16 = 0.1 Nd16 = 1.852 νd16 = 14.02 r17 = 13.099 d17 = D17 (Aspheric surface) r18 = 14.223 d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34 (Aspheric surface) r19 = −42.909 d19 = D19 r20 = ∞ d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84 r21 = ∞ d21 = 0.8 r22 = ∞ d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14 r23 = ∞ d23 = D23 Aspherical coefficients  5th surface k = 0 A4 = 6.45893E−06 A6 = 1.37910E−07 A8 = 0  7th surface k = 0 A4 = −2.12805E−06 A6 = 1.24854E−06 A8 = −5.50277E−08  8th surface k = 0 A4 = −3.36684E−04 A6 = 1.67990E−06 A8 = −4.39469E−07 12th surface k = 0 A4 = 7.11651E−05 A6 = 4.18868E−06 A8 = −7.13660E−08 14th surface k = 0 A4 = 5.75134E−04 A6 = 1.71545E−05 A8 = 1.92117E−07 17th surface k = 0 A4 = 3.19443E−05 A6 = −2.58744E−06 A8 = 0.00000E+00 18th surface k = 0 A4 = −1.27513E−06 A6 = −4.93312E−08 A8 = −9.86622E−09 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.026 13.701 17.994 FNO. 2.85 4.22 5.29 D6 0.8 11.11 12.22 D10 12.81 2.5 1.4 D11 10.02 4 1.19 D14 1.7 10.83 14.52 D17 2.97 2.24 2.94 D19 4.47 2.09 0.5 D23 1.36 1.36 1.36

Twenty Fourth Embodiment

FIG. 47 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty fourth embodiment of the present invention.

FIG. 48A, FIG. 48B, and FIG. 48C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty fourth embodiment, where, FIG. 48A shows the state at the wide angle end, FIG. 48B shows the intermediate state, and FIG. 48C shows the state at the telephoto end.

The zoom lens of the twenty fourth embodiment, as shown in FIG. 47, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refracting power as a whole.

The second lens group G2 includes a biconcave lens L121 and a positive meniscus lens L122 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a biconvex lens L131 and a biconcave lens L132, and has a positive refracting power as a whole.

The fourth lens group G4 includes negative meniscus lens L141 having a convex surface directed toward the object side and a positive meniscus lens L142 having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L142 having the convex surface directed toward the object side is a lens having a thin center-thickness.

The fifth lens group G5 includes a positive meniscus lens L151 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward an image side, the aperture stop S is fixed, the third lens group G3 moves toward the object side, the fourth lens group G4 moves once toward the image side, and then moves toward the object side, and the fifth lens group G5 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L113 in the first lens group G1, both surfaces of the biconcave lens L121 in the second lens group G2, a surface on the object side of the biconvex lens L131 and a surface on the image side of the biconcave lens L132 in the third lens group G3, a surface on the image side of the positive meniscus lens L142 having the convex surface directed toward the object side in the fourth lens group G4, and a surface on the object side of the positive meniscus lens L151 having the convex surface directed toward the object side in the fifth lens group G5.

Next, numerical data of the twenty fourth embodiment will be enumerated.

Numerical data 24 r1 = 25.378 d1 = 1 Nd1 = 1.8061 νd1 = 40.92 r2 = 9.203 d2 = 3.71 r3 = ∞ d3 = 12 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.3 r5 = 47.204 d5 = 3.54 Nd5 = 1.741 νd5 = 52.64 (Aspheric surface) r6 = −22.238 d6 = D6 r7 = −59.956 d7 = 0.8 Nd7 = 1.8061 νd7 = 40.92 (Aspheric surface) r8 = 6.912 d8 = 0.7 (Aspheric surface) r9 = 9.696 d9 = 2.2 Nd9 = 1.7552 νd9 = 27.51 r10 = 218.437 d10 = D10 r11 = Aperture stop d11 = D11 r12 = 7.687 d12 = 6.26 Nd12 = 1.6935 νd12 = 53.21 (Aspheric surface) r13 = −12.317 d13 = 0.7 Nd13 = 1.84666 νd13 = 23.78 r14 = 29.010 d14 = D14 (Aspheric surface) r15 = 15.343 d15 = 0.6 Nd15 = 1.58267 νd15 = 46.42 r16 = 7.801 d16 = 0.1 Nd16 = 1.65228 νd16 = 12 r17 = 7.969 d17 = D17 (Aspheric surface) r18 = 10.663 d18 = 1.8 Nd18 = 1.7725 νd18 = 49.6 (Aspheric surface) r19 = 182.013 d19 = D19 r20 = ∞ d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84 r21 = ∞ d21 = 0.8 r22 = ∞ d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14 r23 = ∞ d23 = D23 Aspherical coefficients  5th surface k = 0 A4 = 1.56293E−05 A6 = 1.88151E−07 A8 = 0  7th surface k = 0 A4 = −3.52622E−04 A6 = 1.94506E−05 A8 = −2.27135E−07  8th surface k = 0 A4 = −6.69309E−04 A6 = 1.97817E−05 A8 = −2.00038E−07 12th surface k = 0 A4 = 7.43312E−05 A6 = 1.49461E−06 A8 = 2.68705E−08 14th surface k = 0 A4 = 7.23485E−04 A6 = 9.02163E−06 A8 = 9.80727E−07 17th surface k = 0 A4 = 6.18056E−06 A6 = 2.05787E−06 A8 = 0.00000E+00 18th surface k = 0 A4 = −3.12291E−05 A6 = 9.09050E−06 A8 = −1.55608E−07 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.1 13.42 17.995 FNO. 3.37 5.23 6.58 D6 3.92 9.22 9.7 D10 12.74 2.46 0.47 D11 6.15 2.51 0.43 D14 1.57 12.09 15.5 D17 1.33 2 3.24 D19 4.75 1.4 0.53 D23 1.37 1.37 1.37

Twenty Fifth Embodiment

FIG. 49 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty fifth embodiment of the present invention.

FIG. 50A, FIG. 50B, and FIG. 50C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty fifth embodiment, where, FIG. 50A shows the state at the wide angle end, FIG. 50B shows the intermediate state, and FIG. 50C shows the state at the telephoto end.

The zoom lens of the twenty fifth embodiment, as shown in FIG. 49, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refracting power as a whole.

The second lens group G2 includes a biconcave lens L121 and a positive meniscus lens L122 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a biconvex lens L131 and a biconcave lens L132, and has a positive refracting power as a whole.

The fourth lens group G4 includes a negative meniscus lens L141 having a convex surface directed toward the object side and a negative meniscus lens L142 having a convex surface directed toward the object side, and has a negative refracting power as a whole. The negative meniscus lens L142 having the convex surface directed toward the object side is a lens having a thin center-thickness.

The fifth lens group G5 includes a positive meniscus lens L151 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward an image side, the aperture stop S is fixed, the third lens group G3 moves toward the object side, the fourth lens group G4 moves once toward the image side, and then moves toward the object side, and the fifth lens group G5 moves toward the image side.

An aspheric surface is provided on a surface on the object side of the biconvex lens L113 in the first lens group G1, both surfaces of the biconcave lens L121 in the second lens group G2, a surface on the object side of the biconvex lens L131 and a surface on the image side of the biconcave lens L132 in the third lens group G3, a surface on the image side of the negative meniscus lens L142 having the convex surface directed toward the object side in the fourth lens group G4, and a surface on the object side of the positive meniscus lens L151 having the convex surface directed toward the object side in the fifth lens group. G5.

Next, numerical data of the twenty fifth embodiment will be enumerated.

Numerical data 25 r1 = 22.245 d1 = 1 Nd1 = 1.8061 νd1 = 40.92 r2 = 8.826 d2 = 3.45 r3 = ∞ d3 = 12 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.3 r5 = 36.134 d5 = 3.54 Nd5 = 1.741 νd5 = 52.64 (Aspheric surface) r6 = −26.96 d6 = D6 r7 = −114.807 d7 = 0.8 Nd7 = 1.8061 νd7 = 40.92 (Aspheric surface) r8 = 6.407 d8 = 0.7 (Aspheric surface) r9 = 8.98 d9 = 2.2 Nd9 = 1.7552 νd9 = 27.51 r10 = 126.659 d10 = D10 r11 = Aperture stop d11 = D11 r12 = 7.716 d12 = 6.16 Nd12 = 1.6935 νd12 = 53.21 (Aspheric surface) r13 = −11.934 d13 = 0.7 Nd13 = 1.84666 νd13 = 23.78 r14 = 29.278 d14 = D14 (Aspheric surface) r15 = 11.15 d15 = 0.6 Nd15 = 1.48749 νd15 = 70.23 r16 = 6.803 d16 = 0.1 Nd16 = 1.59885 νd16 = 6.52 r17 = 6.686 d17 = D17 (Aspheric surface) r18 = 10.149 d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34 (Aspheric surface) r19 = 93.849 d19 = D19 r20 = ∞ d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84 r21 = ∞ d21 = 0.8 r22 = ∞ d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14 r23 = ∞ d23 = D23 Aspherical coefficients  5th surface k = 0 A4 = 3.04484E−05 A6 = 2.47332E−07 A8 = 0  7th surface k = 0 A4 = −3.29779E−04 A6 = 1.94880E−05 A8 = −2.30770E−07  8th surface k = 0 A4 = −6.90117E−04 A6 = 1.82143E−05 A8 = −2.09696E−07 12th surface k = 0 A4 = 7.14236E−05 A6 = 1.72782E−06 A8 = 2.44480E−08 14th surface k = 0 A4 = 6.86121E−04 A6 = 1.02728E−05 A8 = 8.39843E−07 17th surface k = 0 A4 = −8.14853E−05 A6 = 6.69357E−07 A8 = 0.00000E+00 18th surface k = 0 A4 = −7.16543E−05 A6 = 1.04773E−05 A8 = −1.54753E−07 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.1 13.42 17.995 FNO. 3.21 5.1 6.43 D6 2.85 10.17 10.67 D10 10.88 2.65 0.77 D11 6.94 2.58 0.4 D14 1.17 12.06 15.56 D17 1.33 2.02 3.28 D19 4.75 1.39 0.49 D23 1.37 1.37 1.37

Twenty Sixth Embodiment

FIG. 51 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty sixth embodiment of the present invention.

FIG. 52A, FIG. 52B, and FIG. 52C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty sixth embodiment, where, FIG. 52A shows the state at the wide angle end, FIG. 52B shows the intermediate state, and FIG. 52C shows the state at the telephoto end.

The zoom lens of the twenty sixth embodiment, as shown in FIG. 51, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refracting power as a whole.

The second lens group G2 includes a biconcave lens L121 and a positive meniscus lens L122 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a biconvex lens L131 and a biconcave lens L132, and has a positive refracting power as a whole.

The fourth lens group G4 includes a cemented lens which is formed by a negative meniscus lens L141 having a convex surface directed toward the object side and a positive meniscus lens L142 having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L142 having the convex surface directed toward the object side is a lens having a thin center-thickness.

The fifth lens group G5 includes a positive meniscus lens L151 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward an image side, the aperture stop S is fixed, the third lens group G3 moves toward the object side, the fourth lens group G4 moves once toward the image side, and then moves toward the object side, and the fifth lens group G5 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L113 in the first lens group G1, both surfaces of the biconcave lens L121 in the second lens group G2, a surface on the object side of the biconvex lens L131 and a surface on the image side of the biconcave lens L132 in the third lens group G3, a surface on the image side of the positive meniscus lens L142 having the convex surface directed toward the object side in the fourth lens group G4, and a surface on the object side of the positive meniscus lens L151 having the convex surface directed toward the object side in the fifth lens group G5.

Next, numerical data of the twenty sixth embodiment will be enumerated.

Numerical data 26 r1 = 23.3 d1 = 1 Nd1 = 1.8061 νd1 = 40.92 r2 = 8.963 d2 = 3.66 r3 = ∞ d3 = 12 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.3 r5 = 43.373 d5 = 3.54 Nd5 = 1.741 νd5 = 52.64 (Aspheric surface) r6 = −23.569 d6 = D6 r7 = −60.807 d7 = 0.8 Nd7 = 1.8061 νd7 = 40.92 (Aspheric surface) r8 = 6.844 d8 = 0.7 (Aspheric surface) r9 = 9.537 d9 = 2.2 Nd9 = 1.7552 νd9 = 27.51 r10 = 225.725 d10 = D10 r11 = Aperture stop d12 = D11 r12 = 7.662 d12 = 6.34 Nd12 = 1.6935 νd12 = 53.21 (Aspheric surface) r13 = −11.718 d13 = 0.7 Nd13 = 1.84666 νd13 = 23.78 r14 = 28.761 d14 = D14 (Aspheric surface) r15 = 15.01 d15 = 0.6 Nd15 = 1.48749 νd15 = 70.23 r16 = 7.96 d16 = 0.1 Nd16 = 1.79525 νd16 = 9.95 r17 = 7.975 d17 = D17 (Aspheric surface) r18 = 11.632 d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34 (Aspheric surface) r19 = 234.357 d19 = D19 r20 = ∞ d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84 r21 = ∞ d21 = 0.8 r22 = ∞ d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14 r23 = ∞ d23 = D23 Aspherical coefficients  5th surface k = 0 A4 = 2.10592E−05 A6 = 2.04017E−07 A8 = 0  7th surface k = 0 A4 = −2.74185E−04 A6 = 1.68715E−05 A8 = −1.96216E−07  8th surface k = 0 A4 = −5.92738E−04 A6 = 1.71764E−05 A8 = −2.01706E−07 12th surface k = 0 A4 = 6.68932E−05 A6 = 1.80769E−06 A8 = 1.66788E−08 14th surface k = 0 A4 = 7.22351E−04 A6 = 1.11715E−05 A8 = 9.20361E−07 17th surface k = 0 A4 = −2.32260E−05 A6 = 6.22598E−07 A8 = 0.00000E+00 18th surface k = 0 A4 = −5.31997E−05 A6 = 8.76368E−06 A8 = −1.43841E−07 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.1 13.42 17.995 FNO. 3.45 5.14 6.51 D6 3.24 9.87 10.77 D10 13.65 2.39 0.92 D11 5.85 3.12 0.4 D14 1.48 11.6 14.74 D17 1.34 2.07 3.37 D19 4.75 1.33 0.4 D23 1.37 1.37 1.37

Twenty Seventh Embodiment

FIG. 53 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty seventh embodiment of the present invention.

FIG. 54A, FIG. 54B, and FIG. 54C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty seventh embodiment, where, FIG. 54A shows the state at the wide angle end, FIG. 54B shows the intermediate state, and FIG. 54C shows the state at the telephoto end.

The zoom lens of the twenty seventh embodiment, as shown in FIG. 53, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refracting power as a whole.

The second lens group G2 includes a biconcave lens L121 and a positive meniscus lens L122 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a biconvex lens L131 and a biconcave lens L132, and has a positive refracting power as a whole.

The fourth lens group G4 includes a cemented lens which is formed by a negative meniscus lens L141 having a convex surface directed toward the object side and a positive meniscus lens L142 having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L142 having the convex surface directed toward the object side is a lens having a thin center-thickness.

The fifth lens group G5 includes a biconvex lens L151, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward an image side, the aperture stop S is fixed, the third lens group G3 moves toward the object side, the fourth lens group G4 moves once toward the image side, and then moves toward the object side, and the fifth lens group G5 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L113 in the first lens group G1, both surfaces of the biconcave lens L121 in the second lens group G2, a surface on the object side of the biconvex lens L131 and a surface on the image side of the biconcave lens L132 in the third lens group G3, a surface on the image side of the positive meniscus lens L142 having the convex surface directed toward the object side in the fourth lens group G4, and a surface on the object side of the biconvex lens L151 in the fifth lens group G5.

Next, numerical data of the twenty seventh embodiment will be enumerated.

Numerical data 27 r1 = 23.417 d1 = 1 Nd1 = 1.8061 νd1 = 40.92 r2 = 8.991 d2 = 3.7 r3 = ∞ d3 = 12 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.3 r5 = 42.756 d5 = 3.54 Nd5 = 1.741 νd5 = 52.64 (Aspheric surface) r6 = −23.653 d6 = D6 r7 = −62.454 d7 = 0.8 Nd7 = 1.8061 νd7 = 40.92 (Aspheric surface) r8 = 6.820 d8 = 0.7 (Aspheric surface) r9 = 9.53 d9 = 2.2 Nd9 = 1.7552 νd9 = 27.51 r10 = 216.48 d10 = D10 r11 = Aperture stop d11 = D11 r12 = 7.667 d12 = 6.33 Nd12 = 1.6935 νd12 = 53.21 (Aspheric surface) r13 = −11.715 d13 = 0.7 Nd13 = 1.84666 νd13 = 23.78 r14 = 28.801 d14 = D14 (Aspheric surface) r15 = 16.547 d15 = 0.6 Nd15 = 1.48749 νd15 = 70.23 r16 = 8.396 d16 = 0.1 Nd16 = 1.9712 νd16 = 12.88 r17 = 8.453 d17 = D17 (Aspheric surface) r18 = 12.298 d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34 (Aspheric surface) r19 = −1666.051 d19 = D19 r20 = ∞ d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84 r21 = ∞ d21 = 0.8 r22 = ∞ d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14 r23 = ∞ d23 = D23 Aspherical coefficients 5th surface k = 0 A4 = 1.97863E−05 A6 = 1.99130E−07 A8 = 0 7th surface k = 0 A4 = −2.76063E−04 A6 = 1.66842E−05 A8 = −1.87307E−07 8th surface k = 0 A4 = −6.00048E−04 A6 = 1.66821E−05 A8 = −1.83573E−07 12th surface k = 0 A4 = 6.73087E−05 A6 = 1.83455E−06 A8 = 1.35252E−08 14th surface k = 0 A4 = 7.20573E−04 A6 = 1.11057E−05 A8 = 9.05706E−07 17th surface k = 0 A4 = −7.32245E−06 A6 = 3.35000E−07 A8 = 0.00000E+00 18th surface k = 0 A4 = −5.22378E−05 A6 = 8.59323E−06 A8 = −1.53966E−07 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.1 13.42 17.995 FNO. 3.41 5.12 6.49 D6 3.39 9.88 10.83 D10 13.35 2.4 0.93 D11 6.12 3.14 0.4 D14 1.47 11.6 14.69 D17 1.34 2.07 3.38 D19 4.75 1.33 0.4 D23 1.37 1.37 1.37

Twenty Eighth Embodiment

FIG. 55 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty eighth embodiment of the present invention.

FIG. 56A, FIG. 56B, and FIG. 56C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty eighth embodiment, where, FIG. 56A shows the state at the wide angle end, FIG. 56B shows the intermediate state, and FIG. 56C shows the state at the telephoto end.

The zoom lens of the twenty eighth embodiment, as shown in FIG. 55, has in order from an object side thereof, a first lens group G1, a second lens group G2, and aperture stop S, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refracting power as a whole.

The second lens group G2 includes a biconcave lens L121 and a positive meniscus lens L122 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a biconvex lens L131 and a biconcave lens L132, and has a positive refracting power as a whole.

The fourth lens group G4 includes a cemented lens which is formed by a negative meniscus lens L141 having a convex surface directed toward the object side and a negative meniscus lens L142 having a convex surface directed toward the object side, and has a negative refracting power as a whole. The negative meniscus lens L142 having the convex surface directed toward the object side is a lens having a thin center-thickness.

The fifth lens group G5 includes a positive meniscus lens L151 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward an image side, the aperture stop S is fixed, the third lens group G3 moves toward the object side, the fourth lens group G4 moves once toward the image side, and then moves toward the object side, and the fifth lens group G5 moves toward the image side.

An aspheric surface is provided on a surface on the object side of the biconvex lens L113 in the first lens group G1, both surfaces of the concave lens L121 in the second lens group G2, a surface on the object side of the biconvex lens L131 and a surface on the image side of the biconcave lens L132 in the third lens group G3, a surface on the image side of the negative meniscus lens L142 having the convex surface directed toward the object side in the fourth lens group G4, and a surface on the object side of the positive meniscus lens L151 having the convex surface directed toward the object side in the fifth lens group G5.

Next, numerical data of the twenty eighth embodiment will be enumerated.

Numerical data 28 r1 = 23.178 d1 = 1 Nd1 = 1.8061 νd1 = 40.92 r2 = 8.968 d2 = 3.67 r3 = ∞ d3 = 12 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.3 r5 = 42.366 d5 = 3.54 Nd5 = 1.741 νd5 = 52.64 (Aspheric surface) r6 = −23.47 d6 = D6 r7 = −66.184 d7 = 0.8 Nd7 = 1.8061 νd7 = 40.92 (Aspheric surface) r8 = 6.725 d8 = 0.7 (Aspheric surface) r9 = 9.362 d9 = 2.2 Nd9 = 1.7552 νd9 = 27.51 r10 = 168.719 d10 = D10 r11 = Aperture stop d11 = D11 r12 = 7.677 d12 = 6.32 Nd12 = 1.6935 νd12 = 53.21 (Aspheric surface) r13 = −11.657 d13 = 0.7 Nd13 = 1.84666 νd13 = 23.78 r14 = 28.815 d14 = D14 (Aspheric surface) r15 = 16.437 d15 = 0.6 Nd15 = 1.48749 νd15 = 70.23 r16 = 8.459 d16 = 0.1 Nd16 = 2.0512 νd16 = 6.28 r17 = 8.423 d17 = D17 (Aspheric surface) r18 = 11.783 d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34 (Aspheric surface) r19 = 490.283 d19 = D19 r20 = ∞ d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84 r21 = ∞ d21 = 0.8 r22 = ∞ d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14 r23 = ∞ d23 = D23 Aspherical coefficients 5th surface k = 0 A4 = 1.89496E−05 A6 = 1.97953E−07 A8 = 0 7th surface k = 0 A4 = −2.76791E−04 A6 = 1.68717E−05 A8 = −1.97472E−07 8th surface k = 0 A4 = −6.09891E−04 A6 = 1.70615E−05 A8 = −2.17636E−07 12th surface k = 0 A4 = 6.94450E−05 A6 = 1.97650E−06 A8 = 1.24007E−08 14th surface k = 0 A4 = 7.23654E−04 A6 = 1.11472E−05 A8 = 9.36169E−07 17th surface k = 0 A4 = −2.39579E−05 A6 = −3.59629E−09 A8 = 0.00000E+00 18th surface k = 0 A4 = −7.13942E−05 A6 = 8.39629E−06 A8 = −1.49327E−07 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.1 13.42 17.994 FNO. 3.36 5.08 6.45 D6 3.34 9.92 10.92 D10 12.91 2.49 1.12 D11 6.71 3.27 0.4 D14 1.48 11.56 14.61 D17 1.34 2.06 3.36 D19 4.75 1.34 0.42 D23 1.37 1.37 1.37

Twenty Ninth Embodiment

FIG. 57 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty ninth embodiment of the present invention.

FIG. 58A, FIG. 58B, and FIG. 58C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty ninth embodiment, where, FIG. 58A shows the state at the wide angle end, FIG. 58B shows the intermediate state, and FIG. 58C shows the state at the telephoto end.

The zoom lens of the twenty ninth embodiment, as shown in FIG. 57, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group G4. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L211 having a convex surface directed toward the object side, a prism L212, and a cemented lens which is formed by a biconvex lens L213 and a biconcave lens L214, and has a negative refracting power as a whole.

The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward an image side, and has a positive refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a negative meniscus lens L231 having a concave surface directed toward the object side and a positive meniscus lens L232 having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L232 having the concave surface directed toward the object side is a lens having a thin center-thickness.

The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward the object side, the aperture stop S is fixed, the third lens group G3 moves toward the image side, and the fourth lens group G4 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L213 in the first lens group G1, a surface on the object side of the biconvex lens L221 in the second lens group G2, a surface on the image side of the positive meniscus lens L232 having the concave surface directed toward the object side in the third lens group G3, and a surface on the object side of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of the twenty ninth embodiment will be enumerated.

Numerical data 29 r1 = 53.184 d1 = 1.1 Nd1 = 1.7432 νd1 = 49.34 r2 = 11.873 d2 = 3 r3 = ∞ d3 = 12.5 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.4 r5 = 59.366 d5 = 2.2 Nd5 = 1.883 νd5 = 40.76 (Aspheric surface) r6 = −20.517 d6 = 0.7 Nd6 = 1.48749 νd6 = 70.23 r7 = 13.429 d7 = D7 r8 = 13.703 d8 = 3.5 Nd8 = 1.7432 νd8 = 49.34 (Aspheric surface) r9 = −12.5 d9 = 0.7 Nd9 = 1.84666 νd9 = 23.78 r10 = −54.992 d10 = D10 r11 = Aperture stop d11 = D11 r12 = −8.545 d12 = 0.7 Nd12 = 1.51742 νd12 = 52.43 r13 = −100 d13 = 0.35 Nd13 = 1.60687 νd13 = 27.03 r14 = −29.442 d14 = D14 (Aspheric surface) r15 = 11.068 d15 = 3.5 Nd15 = 1.6935 νd15 = 53.21 (Aspheric surface) r16 = −7.5 d16 = 0.7 Nd16 = 1.84666 νd16 = 23.78 r17 = −16.423 d17 = D17 r18 = ∞ d18 = 1.44 Nd18 = 1.54771 νd18 = 62.84 r19 = ∞ d19 = 0.8 r20 = ∞ d20 = 0.6 Nd20 = 1.51633 νd20 = 64.14 r21 = ∞ d21 = D21 Aspherical coefficients 5th surface k = 0 A4 = 2.67481E−05 A6 = 1.21868E−07 A8 = 0.00000E+00 8th surface k = 0 A4 = −2.11732E−05 A6 = −1.15590E−07 A8 = −4.21441E−07 14th surface k = 0 A4 = −3.07942E−04 A6 = 2.46538E−06 A8 = −1.28129E−06 15th surface k = 0 A4 = −2.90469E−04 A6 = 3.87680E−07 A8 = 5.27383E−08 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 5.999 13.697 17.987 FNO. 2.84 3.39 3.74 D7 13.8 3.92 0.8 D10 1.6 11.49 14.61 D11 1.41 6.01 9.1 D14 6.45 4.93 3 D17 5.45 2.36 1.2 D21 1.36 1.36 1.36

Thirtieth Embodiment

FIG. 59 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirtieth embodiment of the present invention.

FIG. 60A, FIG. 60B, and FIG. 60C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirtieth embodiment, where, FIG. 60A shows the state at the wide angle end, FIG. 60B shows the intermediate state, and FIG. 60C shows the state at the telephoto end.

The zoom lens of the thirtieth embodiment, as shown in FIG. 59, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group G4. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L212, and a cemented lens which is formed by a biconvex lens L213 and a biconcave lens L214, and has a negative refracting power as a whole.

The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having the convex surface directed toward an image side, and has a positive refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a negative meniscus lens L231 having a concave surface directed toward the object side and a positive meniscus lens L232 having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L232 having the concave surface directed toward the object side is a lens having a thin center-thickness.

The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward the object side, the aperture stop S is fixed, the third lens group G3 moves toward the image side, and the fourth lens group G4 moves toward the image side.

An aspheric surface is provided on a surface on the object side of the biconvex lens L213 in the first lens group G1, a surface on the object side of the biconvex lens L221 in the second lens group G2, a surface on the image side of the positive meniscus lens L232 having the concave surface directed toward the object side in the third lens group G3, and a surface on the object side of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of the thirtieth embodiment will be enumerated.

Numerical data 30 r1 = 37.87 d1 = 1.1 Nd1 = 1.72 νd1 = 41.98 r2 = 10.224 d2 = 3 r3 = ∞ d3 = 12.5 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.4 r5 = 89.903 d5 = 2.2 Nd5 = 1.883 νd5 = 40.76 (Aspheric surface) r6 = −14.853 d6 = 0.7 Nd6 = 1.48749 νd6 = 70.23 r7 = 14.608 d7 = D7 r8 = 14.897 d8 = 3.5 Nd8 = 1.7432 νd8 = 49.34 (Aspheric surface) r9 = −12.5 d9 = 0.7 Nd9 = 1.84666 νd9 = 23.78 r10 = −58.416 d10 = D10 r11 = Aperture stop d11 = D11 r12 = −8.762 d12 = 0.7 Nd12 = 1.51742 νd12 = 52.43 r13 = −100 d13 = 0.35 Nd13 = 1.60258 νd13 = 18.58 r14 = −31.451 d14 = D14 (Aspheric surface) r15 = 10.327 d15 = 3.5 Nd15 = 1.6935 νd15 = 53.21 (Aspheric surface) r16 = −7.5 d16 = 0.7 Nd16 = 1.84666 νd16 = 23.78 r17 = −17.752 d17 = D17 r18 = ∞ d18 = 1.44 Nd18 = 1.54771 νd18 = 62.84 r19 = ∞ d19 = 0.8 r20 = ∞ d20 = 0.6 Nd20 = 1.51633 νd20 = 64.14 r21 = ∞ d21 = D21 Aspherical coefficients 5th surface k = 0 A4 = 1.56745E−05 A6 = 1.40375E−07 A8 = 0 8th surface k = 0 A4 = −5.42647E−06 A6 = −8.38801E−08 A8 = 0.00000E+00 14th surface k = 0 A4 = −2.46472E−04 A6 = −2.77422E−07 A8 = 0.00000E+00 15th surface k = 0 A4 = −2.66703E−04 A6 = 2.98736E−07 A8 = 0.00000E+00 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.02 13.7 17.998 FNO. 2.84 3.52 3.89 D7 14.02 3.96 0.8 D10 1.6 11.67 14.82 D11 1.4 7.11 10.07 D14 7.1 4.6 3 D17 5.76 2.55 1.19 D21 1.36 1.36 1.36

Thirty First Embodiment

FIG. 61 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty first embodiment of the present invention.

FIG. 62A, FIG. 62B, and FIG. 62C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty first embodiment, where, FIG. 62A shows the state at the wide angle end, FIG. 62B shows the intermediate state, and FIG. 62C shows the state at the telephoto end.

The zoom lens of the thirty first embodiment, as shown in FIG. 61, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group G4. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L211 having a convex surface directed toward the object side, a prism L212, and a cemented lens which is formed by a biconvex lens L213 and a biconcave lens L214, and has a negative refracting power as a whole.

The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward an image side, and has a positive refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a negative meniscus lens L231 having a concave surface directed toward the object side and a positive meniscus lens L232 having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L232 having the concave surface directed toward the object side is a lens having a thin center-thickness.

The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward the object side, the aperture stop S is fixed, the third lens group G3 moves toward the image side, and the fourth lens group G4 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L213 in the first lens group G1, a surface toward the object side of the biconvex lens L221 in the second lens group G2, a surface toward the image side of the positive meniscus lens L232 having the concave surface directed toward the object side in the third lens group G3, and a surface toward the object side of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of the thirty first embodiment will be enumerated.

Numerical data 31 r1 = 53.073 d1 = 1.1 Nd1 = 1.7432 νd1 = 49.34 r2 = 11.88 d2 = 3 r3 = ∞ d3 = 12.5 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.4 r5 = 59.240 d5 = 2.2 Nd5 = 1.883 νd5 = 40.76 (Aspheric surface) r6 = −20.497 d6 = 0.7 Nd6 = 1.48749 νd6 = 70.23 r7 = 13.436 d7 = D7 r8 = 13.696 d8 = 3.5 Nd8 = 1.7432 νd8 = 49.34 (Aspheric surface) r9 = −12.5 d9 = 0.7 Nd9 = 1.84666 νd9 = 23.78 r10 = −54.875 d10 = D10 r11 = Aperture stop d11 = D11 r12 = −8.541 d12 = 0.7 Nd12 = 1.51742 νd12 = 52.43 r13 = −100 d13 = 0.35 Nd13 = 1.69556 νd13 = 25.02 r14 = −29.479 d14 = D14 (Aspheric surface) r15 = 11.078 d15 = 3.5 Nd15 = 1.6935 νd15 = 53.21 (Aspheric surface) r16 = −7.5 d16 = 0.7 Nd16 = 1.84666 νd16 = 23.78 r17 = −16.449 d17 = D17 r18 = ∞ d18 = 1.44 Nd18 = 1.54771 νd18 = 62.84 r19 = ∞ d19 = 0.8 r20 = ∞ d20 = 0.6 Nd20 = 1.51633 νd20 = 64.14 r21 = ∞ d21 = D21 Aspherical coefficients 5th surface k = 0 A4 = 2.61751E−05 A6 = 1.15939E−07 A8 = 0 8th surface k = 0 A4 = −2.16066E−05 A6 = −9.35544E−08 A8 = 0.00000E+00 14th surface k = 0 A4 = −3.03099E−04 A6 = 4.81429E−06 A8 = 0.00000E+00 15th surface k = 0 A4 = −2.89734E−04 A6 = 2.36417E−07 A8 = 0.00000E+00 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 5.97 13.634 17.897 FNO. 2.82 3.37 3.71 D7 13.8 3.92 0.8 D10 1.6 11.49 14.61 D11 1.41 6.01 9.1 D14 6.45 4.93 3 D17 5.45 2.36 1.2 D21 1.1 1.11 1.12

Thirty Second Embodiment

FIG. 63 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty second embodiment of the present invention.

FIG. 64A, FIG. 64B, and FIG. 64C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty second embodiment, where, FIG. 64A shows the state at the wide angle end, FIG. 64B shows the intermediate state, and FIG. 64C shows the state at the telephoto end.

The zoom lens of the thirty second embodiment, as shown in FIG. 63, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group G4. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L211 having a convex surface directed toward the object side, a prism L212, and a cemented lens which is formed by a biconvex lens L213 and a biconcave lens L214, and has a negative refracting power as a whole.

The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward an image side, and has a positive refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a negative meniscus lens L231 having a concave surface directed toward the object side and a positive meniscus lens L232 having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L232 having the concave surface directed toward the object side is a lens having a thin center-thickness.

The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward the object side, the aperture stop S is fixed, the third lens group G3 moves toward the image side, and the fourth lens group G4 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L213 in the first lens group G1, a surface on the object side of the biconvex lens L221 in the second lens group G2, a surface on the image side of the positive meniscus lens L232 having the concave surface directed toward the object side in the third lens group G3, and a surface on the object side of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of the thirty second embodiment will be enumerated.

Numerical data 32 r1 = 35.882 d1 = 1.1 Nd1 = 1.72 νd1 = 41.98 r2 = 11.389 d2 = 3 r3 = ∞ d3 = 12.5 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.4 r5 = 1449.208 d5 = 2.2 Nd5 = 1.883 νd5 = 40.76 (Aspheric surface) r6 = −20.294 d6 = 0.7 Nd6 = 1.48749 νd6 = 70.23 r7 = 13.692 d7 = D7 r8 = 13.337 d8 = 3.5 Nd8 = 1.7432 νd8 = 49.34 (Aspheric surface) r9 = −12.5 d9 = 0.7 Nd9 = 1.84666 νd9 = 23.78 r10 = −35.434 d10 = D10 r11 = Aperture stop d11 = D11 r12 = −9.636 d12 = 0.7 Nd12 = 1.51742 νd12 = 52.43 r13 = −100 d13 = 0.35 Nd13 = 1.72568 νd13 = 18.68 r14 = −47.470 d14 = D14 (Aspheric surface) r15 = 9.153 d15 = 3.5 Nd15 = 1.6935 νd15 = 53.21 (Aspheric surface) r16 = −7.5 d16 = 0.7 Nd16 = 1.84666 νd16 = 23.78 r17 = −27.617 d17 = D17 r18 = ∞ d18 = 1.44 Nd18 = 1.54771 νd18 = 62.84 r19 = ∞ d19 = 0.8 r20 = ∞ d20 = 0.6 Nd20 = 1.51633 νd20 = 64.14 r21 = ∞ d21 = D21 Aspherical coefficients 5th surface k = 0 A4 = 4.26368E−05 A6 = 2.02030E−07 A8 = 0 8th surface k = 0 A4 = −4.51766E−05 A6 = −2.67569E−07 A8 = 0.00000E+00 14th surface k = 0 A4 = −2.01076E−04 A6 = 2.16748E−06 A8 = 0.00000E+00 15th surface k = 0 A4 = −2.54268E−04 A6 = 2.30811E−07 A8 = 0.00000E+00 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.115 13.7 17.987 FNO. 2.84 3.46 3.75 D7 12.73 4.33 0.8 D10 1.58 9.99 13.51 D11 1.41 6.05 10.08 D14 8.06 6.6 2.98 D17 4.78 1.6 1.19

Thirty Third Embodiment

FIG. 65 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty third embodiment of the present invention.

FIG. 66A, FIG. 66B, and FIG. 66C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty third embodiment, where, FIG. 66A shows the state at the wide angle end, FIG. 66B shows the intermediate state, and FIG. 66C shows the state at the telephoto end.

The zoom lens of the thirty third embodiment, as shown in FIG. 65, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group G4. In the diagram, LPF is a low pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L211 having a convex surface directed toward the object side, a prism L212, and a cemented lens which is formed by a biconvex lens L213 and a biconcave lens L214, and has a negative refracting power as a whole.

The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward an image side, and has a positive refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a negative meniscus lens L231 having a concave surface directed toward the object side and a positive meniscus lens L232 having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L232 having the concave surface directed toward the object side is a lens having a thin center-thickness.

The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward the object side, the aperture stop S is fixed, the third lens group G3 moves toward the image side, and the fourth lens group G4 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L213 in the first lens group G1, a surface on the object side of the biconvex lens L221 in the second lens group G2, a surface on the image side of the positive meniscus lens L232 having the concave surface directed toward the object side in the third lens group G3, and a surface on the object side of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of the thirty third embodiment will be enumerated.

Numerical data 33 r1 = 35.571 d1 = 1.1 Nd1 = 1.72 νd1 = 41.98 r2 = 11.248 d2 = 3 r3 = ∞ d3 = 12.5 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.4 r5 = 610.441 d5 = 2.2 Nd5 = 1.883 νd5 = 40.76 (Aspheric surface) r6 = −20.284 d6 = 0.7 Nd6 = 1.48749 νd6 = 70.23 r7 = 14.001 d7 = D7 r8 = 13.614 d8 = 3.5 Nd8 = 1.7432 νd8 = 49.34 (Aspheric surface) r9 = −12.5 d9 = 0.7 Nd9 = 1.84666 νd9 = 23.78 r10 = −35.933 d10 = D10 r11 = Aperture stop d11 = D11 r12 = −9.979 d12 = 0.7 Nd12 = 1.51742 νd12 = 52.43 r13 = −100 d13 = 0.35 Nd13 = 1.852 νd13 = 14.02 r14 = −57.672 d14 = D14 (Aspheric surface) r15 = 9.097 d15 = 3.5 Nd15 = 1.6935 νd15 = 53.21 (Aspheric surface) r16 = −7.5 d16 = 0.7 Nd16 = 1.84666 νd16 = 23.78 r17 = −27.778 d17 = D17 r18 = ∞ d18 = 1.44 Nd18 = 1.54771 νd18 = 62.84 r19 = ∞ d19 = 0.8 r20 = ∞ d20 = 0.6 Nd20 = 1.51633 νd20 = 64.14 r21 = ∞ d21 = D21 Aspherical coefficients  5th surface k = 0 A4 = 4.31813E−05 A6 = 1.95476E−07 A8 = 0  8th surface k = 0 A4 = −4.35637E−05 A6 = −2.46996E−07 A8 = 0.00000E+00 14th surface k = 0 A4 = −1.80555E−04 A6 = 2.30560E−06 A8 = 0.00000E+00 15th surface k = 0 A4 = −2.61526E−04 A6 = 3.69800E−07 A8 = 0.00000E+00 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.108 13.7 17.989 FNO. 2.84 3.49 3.76 D7 12.89 4.45 0.81 D10 1.58 10.03 13.67 D11 1.41 6.36 10.13 D14 8.02 6.38 2.98 D17 4.88 1.58 1.2 D21 1.36 1.36 1.36

Thirty Fourth Embodiment

FIG. 67 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty fourth embodiment of the present invention.

FIG. 68A, FIG. 68B, and FIG. 68C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty fourth embodiment, where, FIG. 68A shows the state at the wide angle end, FIG. 68B shows the intermediate state, and FIG. 68 shows the state at the telephoto end.

The zoom lens of the thirty fourth embodiment, as shown in FIG. 67, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group G4. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L211 having a convex surface directed toward the object side, a prism L212, and a cemented lens which is formed by a biconvex lens L213 and a biconcave lens L214, and has a negative refracting as a whole.

The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward an image side, and has a positive refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a negative meniscus lens L231 having a concave surface directed toward the object side and a positive meniscus lens L232 having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L232 having the concave surface directed toward the object side is a lens having a thin center-thickness.

The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward the object side, the aperture stop S is fixed, the third lens group G3 moves toward the image side, and the fourth lens group G4 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L213 in the first lens group G1, a surface on the object side of the biconvex lens L221 in the second lens group G2, a surface on the image side of the positive meniscus lens L232 having the concave surface directed toward the object side in the third lens group G3, and a surface on the object side of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of the thirty fourth embodiment will be enumerated.

Numerical data 34 r1 = 38.891 d1 = 1.1 Nd1 = 1.7432 νd1 = 49.34 r2 = 9.835 d2 = 3 r3 = ∞ d3 = 12.5 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.4 r5 = 60.054 d5 = 2.2 Nd5 = 1.883 νd5 = 40.76 (Aspheric surface) r6 = −24.469 d6 = 0.7 Nd6 = 1.48749 νd6 = 70.23 r7 = 12.862 d7 = D7 r8 = 15.353 d8 = 3.5 Nd8 = 1.7432 νd8 = 49.34 (Aspheric surface) r9 = −12.5 d9 = 0.7 Nd9 = 1.84666 νd9 = 23.78 r10 = −39.902 d10 = D10 r11 = Aperture stop d11 = D11 r12 = −9.98 d12 = 0.7 Nd12 = 1.51729 νd12 = 65.94 r13 = −100 d13 = 0.35 Nd13 = 1.65228 νd13 = 12.75 r14 = −48.119 d14 = D14 (Aspheric surface) r15 = 11.111 d15 = 3.5 Nd15 = 1.6935 νd15 = 53.21 (Aspheric surface) r16 = −7.5 d16 = 0.7 Nd16 = 1.84666 νd16 = 23.78 r17 = −22.56 d17 = D17 r18 = ∞ d18 = 1.44 Nd18 = 1.54771 νd18 = 62.84 r19 = ∞ d19 = 0.8 r20 = ∞ d20 = 0.6 Nd20 = 1.51633 νd20 = 64.14 r21 = ∞ d21 = D21 Aspherical coefficients  5th surface k = 0 A4 = 7.13925E−05 A6 = 1.71754E−07 A8 = 0  8th surface k = 0 A4 = −3.78743E−05 A6 = −1.60871E−07 A8 = 0.00000E+00 14th surface k = 0 A4 = −4.07707E−04 A6 = 2.30478E−06 A8 = 0.00000E+00 15th surface k = 0 A4 = −3.45182E−04 A6 = 2.31185E−06 A8 = 0.00000E+00 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.101 10.553 17.994 FNO. 3.06 3.65 5.17 D7 17.7 5.59 1.05 D10 5.85 9.39 13.35 D11 0.65 4.63 15.8 D14 5.72 3.86 2.69 D17 5.77 6.71 5.32 D21 1.36 1.36 1.36

Thirty Fifth Embodiment

FIG. 69 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty fifth embodiment of the present invention.

FIG. 70A, FIG. 70B, and FIG. 70C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty fifth embodiment, where, FIG. 70A shows the state at the wide angle end, FIG. 70B shows the intermediate state, and FIG. 70C shows the state at the telephoto end.

The zoom lens of the thirty fifth embodiment, as shown in FIG. 69, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group G4. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L211 having a convex surface directed toward the object side, a prism L212, and a cemented lens which is formed by a biconvex lens L213 and a biconcave lens L214, and has a negative refracting power as a whole.

The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward an image side, and has a positive refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a negative meniscus lens L231 having a concave surface directed toward the object side and a positive meniscus lens L232 having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L232 having the concave surface directed toward the object side is a lens having a thin center-thickness.

The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward the object side, the aperture stop S is fixed, the third lens group G3 moves toward the image side, and the fourth lens group G4 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L213 in the first lens group G1, a surface on the object side of the biconvex lens L221 in the second lens group G2, a surface on the image side of the positive meniscus lens L232 having the concave surface directed toward the object side in the third lens group G3, and a surface on the object side of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of the thirty fifth embodiment will be enumerated.

Numerical data 35 r1 = 57.868 d1 = 1.1 Nd1 = 1.7432 νd1 = 49.34 r2 = 11.248 d2 = 3.05 r3 = ∞ d3 = 12.5 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.4 r5 = 51.247 d5 = 3.42 Nd5 = 1.883 νd5 = 40.76 (Aspheric surface) r6 = −24.561 d6 = 0.9 Nd6 = 1.48749 νd6 = 70.23 r7 = 12.542 d7 = D7 r8 = 14.337 d8 = 7.69 Nd8 = 1.7432 νd8 = 49.34 (Aspheric surface) r9 = −12.5 d9 = 3.98 Nd9 = 1.84666 νd9 = 23.78 r10 = −50.883 d10 = D10 r11 = Aperture stop d11 = D11 r12 = −10.713 d12 = 0.9 Nd12 = 1.52852 νd12 = 58.86 r13 = −100 d13 = 0.35 Nd13 = 1.59885 νd13 = 6.52 r14 = −63.005 d14 = D14 (Aspheric surface) r15 = 9.560 d15 = 4.34 Nd15 = 1.71237 νd15 = 44.16 (Aspheric surface) r16 = −7.5 d16 = 3.5 Nd16 = 1.81657 νd16 = 21.77 r17 = −48.273 d17 = D17 r18 = ∞ d18 = 1.44 Nd18 = 1.54771 νd18 = 62.84 r19 = ∞ d19 = 0.8 r20 = ∞ d20 = 0.6 Nd20 = 1.51633 νd20 = 64.14 r21 = ∞ d21 = D21 Aspherical coefficients  5th surface k = 0 A4 = 6.06374E−05 A6 = 2.96748E−08 A8 = 0  8th surface k = 0 A4 = −3.79953E−05 A6 = −9.01187E−08 A8 = 0.00000E+00 14th surface k = 0 A4 = −4.27739E−04 A6 = 3.55154E−06 A8 = 0.00000E+00 15th surface k = 0 A4 = −3.08817E−04 A6 = 1.61244E−06 A8 = 0.00000E+00 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.101 10.555 17.998 FNO. 3.24 3.5 4.82 D7 18.49 5.99 1.21 D10 0.91 7.03 11.89 D11 0.61 2.38 11.94 D14 6.75 5.1 4.34 D17 4.75 5.22 3.4 D21 1.36 1.36 1.36

Thirty Sixth Embodiment

FIG. 71 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty sixth embodiment of the present invention.

FIG. 72A, FIG. 72B, and FIG. 72C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty sixth embodiment, where, FIG. 72A shows the state at the wide angle end, FIG. 72B shows the intermediate state, and FIG. 72C shows the state at the telephoto end.

The zoom lens of the thirty sixth embodiment, as shown in FIG. 71, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group G4. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L211 having a convex surface directed toward the object side, a prism L212, and a cemented lens which is formed by a biconvex lens L213 and a biconcave lens L214, and has a negative refracting power as a whole.

The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward an image side, and has a positive refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a negative meniscus lens L231 having a concave surface directed toward the object side and a positive meniscus lens L232 having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L232 having the concave surface directed toward the object side is a lens having a thin center-thickness.

The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward the object side, the aperture stop S is fixed, the third lens group G3 moves toward the image side, and the fourth lens group G4 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L213 in the first lens group G1, a surface on the object side of the biconvex lens L221 in the second lens group G2, a surface on the image side of the positive meniscus lens L232 having the concave surface directed toward the object side in the third lens group G3, and a surface on the object side of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of the thirty sixth embodiment will be enumerated.

Numerical data 36 r1 = 62.959 d1 = 1.1 Nd1 = 1.7432 νd1 = 49.34 r2 = 11.433 d2 = 2.98 r3 = ∞ d3 = 12.5 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.4 r5 = 50.756 d5 = 2.79 Nd5 = 1.883 νd5 = 40.76 (Aspheric surface) r6 = −24.668 d6 = 0.9 Nd6 = 1.48749 νd6 = 70.23 r7 = 12.505 d7 = D7 r8 = 14.492 d8 = 7.39 Nd8 = 1.7432 νd8 = 49.34 (Aspheric surface) r9 = −12.5 d9 = 5.86 Nd9 = 1.84666 νd9 = 23.78 r10 = −48.836 d10 = D10 r11 = Aperture stop d11 = D11 r12 = −9.553 d12 = 0.9 Nd12 = 1.53585 νd12 = 55.13 r13 = −100 d13 = 0.35 Nd13 = 1.79525 νd13 = 9.95 r14 = −44.152 d14 = D14 (Aspheric surface) r15 = 9.226 d15 = 4.3 Nd15 = 1.70794 νd15 = 47.46 (Aspheric surface) r16 = −7.5 d16 = 3.48 Nd16 = 1.82618 νd16 = 21.48 r17 = −49.212 d17 = D17 r18 = ∞ d18 = 1.44 Nd18 = 1.54771 νd18 = 62.84 r19 = ∞ d19 = 0.8 r20 = ∞ d20 = 0.6 Nd20 = 1.51633 νd20 = 64.14 r21 = ∞ d21 = D21 Aspherical coefficients  5th surface k = 0 A4 = 6.09647E−05 A6 = 1.57459E−08 A8 = 0  8th surface k = 0 A4 = −3.80323E−05 A6 = −6.55996E−08 A8 = 0.00000E+00 14th surface k = 0 A4 = −4.26592E−04 A6 = 4.19255E−06 A8 = 0.00000E+00 15th surface k = 0 A4 = −3.87754E−04 A6 = 2.28630E−06 A8 = 0.00000E+00 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.1 10.553 17.995 FNO. 3.19 3.47 4.77 D7 18.27 5.85 1.19 D10 0.7 6.91 12.07 D11 0.64 2.49 12.19 D14 5.78 4.42 3.89 D17 4.69 5.18 3.29 D21 1.36 1.36 1.36

Thirty Seventh Embodiment

FIG. 73 is a cross-sectional view along the optical axis showing an optical arrangement at the wide angle end of a zoom lens according to a thirty seventh embodiment of the present invention.

FIG. 74A, FIG. 74B, and FIG. 74C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty seventh embodiment, where, FIG. 74A shows the state at the wide angle end, FIG. 74B shows the intermediate state, and FIG. 74C shows the state at the telephoto end.

The zoom lens of the thirty seventh embodiment, as shown in FIG. 73, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group G4. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L211 having a convex surface directed toward the object side, a prism L212, and a cemented lens which is formed by a biconvex lens L213 and a biconcave lens L214, and has a negative refracting power as a whole.

The second lens group G2 includes a cemented lens which is formed by a biconcave lens L221 and a negative meniscus lens L222 having a convex surface directed toward an image side, and has a positive refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a negative meniscus lens L231 having a concave surface directed toward the object side and a positive meniscus lens L232 having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L232 having the concave surface directed toward the object side is a lens having a thin center-thickness.

The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward the object side, the aperture stop S is fixed, the third lens group G3 moves toward the image side, and the fourth lens group G4 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L213 in the first lens group G1, a surface on the object side of the biconvex lens L221 in the second lens group G2, a surface on the image side of the positive meniscus lens L232 having the concave surface directed toward the object side in the third lens group G3, and a surface on the object side of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of the thirty seventh embodiment will be enumerated.

Numerical data 37 r1 = 68.079 d1 = 1.1 Nd1 = 1.7432 νd1 = 49.34 r2 = 11.633 d2 = 2.99 r3 = ∞ d3 = 12.5 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.4 r5 = 50.301 d5 = 2.33 Nd5 = 1.883 νd5 = 40.76 (Aspheric surface) r6 = −24.516 d6 = 0.9 Nd6 = 1.48749 νd6 = 70.23 r7 = 12.478 d7 = D7 r8 = 14.504 d8 = 7.39 Nd8 = 1.7432 νd8 = 49.34 (Aspheric surface) r9 = −12.5 d9 = 6.85 Nd9 = 1.84666 νd9 = 23.78 r10 = −48.451 d10 = D10 r11 = Aperture stop d11 = D11 r12 = −8.927 d12 = 0.9 Nd12 = 1.53859 νd12 = 53.87 r13 = −100 d13 = 0.35 Nd13 = 1.9712 νd13 = 12.88 r14 = −38.346 d14 = D14 (Aspheric surface) r15 = 8.915 d15 = 4.15 Nd15 = 1.70159 νd15 = 48.9 (Aspheric surface) r16 = −7.5 d16 = 3 Nd16 = 1.8402 νd16 = 21.32 r17 = −47.582 d17 = D17 r18 = ∞ d18 = 1.44 Nd18 = 1.54771 νd18 = 62.84 r19 = ∞ d19 = 0.8 r20 = ∞ d20 = 0.6 Nd20 = 1.51633 νd20 = 64.14 r21 = ∞ d21 = D21 Aspherical coefficients  5th surface k = 0 A4 = 5.92982E−05 A6 = 5.24010E−09 A8 = 0  8th surface k = 0 A4 = −3.76559E−05 A6 = −4.70537E−08 A8 = 0.00000E+00 14th surface k = 0 A4 = −4.04099E−04 A6 = 4.26752E−06 A8 = 0.00000E+00 15th surface k = 0 A4 = −4.50778E−04 A6 = 2.93020E−06 A8 = 0.00000E+00 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.1 10.553 17.997 FNO. 3.12 3.41 4.64 D7 17.78 5.7 1.23 D10 0.56 6.93 12.47 D11 0.67 2.77 12.22 D14 5.2 3.94 3.41 D17 4.67 4.99 2.88 D21 1.36 1.36 1.36

Thirty Eighth Embodiment

FIG. 75 is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty eighth embodiment of the present invention.

FIG. 76A, FIG. 76B, and FIG. 76C are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty eighth embodiment, where, FIG. 76A shows the state at the wide angle end, FIG. 76B shows the intermediate state, and FIG. 76C shows the state at the telephoto end.

The zoom lens of the thirty eighth embodiment, as shown in FIG. 75, has in order from an object side thereof, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group G4. In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

The first lens group G1 includes a negative meniscus lens L211 having a convex surface directed toward the object side, a prism L212, and a cemented lens which is formed by a biconvex lens L213 and a biconcave lens L214, and has a negative refracting power as a whole.

The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward an image side, and has a positive refracting power as a whole.

The third lens group G3 includes a cemented lens which is formed by a negative meniscus lens L231 having a concave surface directed toward the object side and a positive meniscus lens L232 having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L232 having the concave surface directed toward the object side is a lens having a thin center-thickness.

The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

At the time of zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves toward the object side, the aperture stop S is fixed, the third lens group G3 moves toward the image side, and the fourth lens group G4 moves toward the image side.

An aspheric surface is provided on a surface toward the object side of the biconvex lens L213 in the first lens group G1, a surface on the object side of the biconvex lens L221 in the second lens group G2, a surface on the image side of the positive meniscus lens L232 having the concave surface directed toward the object side in the third lens group G3, and a surface on the object side of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of the thirty eighth embodiment will be enumerated.

Numerical data 38 r1 = 63.79 d1 = 1.1 Nd1 = 1.7432 νd1 = 49.34 r2 = 11.649 d2 = 3.06 r3 = ∞ d3 = 12.5 Nd3 = 1.8061 νd3 = 40.92 r4 = ∞ d4 = 0.4 r5 = 46.980 d5 = 3.3 Nd5 = 1.883 νd5 = 40.76 (Aspheric surface) r6 = −25.318 d6 = 0.9 Nd6 = 1.48749 νd6 = 70.23 r7 = 12.314 d7 = D7 r8 = 14.146 d8 = 7.85 Nd8 = 1.7432 νd8 = 49.34 (Aspheric surface) r9 = −12.5 d9 = 4.47 Nd9 = 1.84666 νd9 = 23.78 r10 = −53.448 d10 = D10 r11 = Aperture stop d11 = D11 r12 = −9.716 d12 = 0.9 Nd12 = 1.53062 νd12 = 57.73 r13 = −100 d13 = 0.35 Nd13 = 2.0512 νd13 = 6.28 r14 = −76.868 d14 = D14 (Aspheric surface) r15 = 8.784 d15 = 4.06 Nd15 = 1.70975 νd15 = 45.62 (Aspheric surface) r16 = −7.5 d16 = 3.07 Nd16 = 1.82469 νd16 = 21.99 r17 = −41.356 d17 = D17 r18 = ∞ d18 = 1.44 Nd18 = 1.54771 νd18 = 62.84 r19 = ∞ d19 = 0.8 r20 = ∞ d20 = 0.6 Nd20 = 1.51633 νd20 = 64.14 r21 = ∞ d21 = D21 Aspherical coefficients  5th surface k = 0 A4 = 5.85091E−05 A6 = 1.63330E−08 A8 = 0  8th surface k = 0 A4 = −3.75473E−05 A6 = −8.44888E−08 A8 = 0.00000E+00 14th surface k = 0 4 = −2.99314E−04 A6 = 3.36694E−06 A8 = 0.00000E+00 15th surface k = 0 A4 = −3.61178E−04 A6 = 1.58918E−06 A8 = 0.00000E+00 Zoom data When D0 (distance from object up to 1st surface) is ∞ wide-angle end intermediate telephoto end Focal length 6.099 10.552 17.993 FNO. 3.03 3.33 4.5 D7 17.47 5.63 1.2 D10 1.14 7.24 12.69 D11 0.62 2.75 11.06 D14 6.52 5.15 4.63 D17 4.84 5.06 3.15 D21 1.36 1.36 1.36

Thirty Ninth Embodiment

Thus, it is possible to use such image forming optical system of the present invention in a photographic apparatus in which an image of an object is photographed by an electronic image pickup element such as a CCD and a CMOS, particularly a digital camera and a video camera, a personal computer, a telephone, and a portable terminal which are examples of an information processing unit, particularly a portable telephone which is easy to carry. Embodiments thereof will be exemplified below.

In FIG. 77 to FIG. 79 show conceptual diagrams of structures in which the image forming optical system according to the present invention is incorporated in a photographic optical system 41 of a digital camera. FIG. 77 is a frontward perspective view showing an appearance of a digital camera 40, FIG. 78 is a rearward perspective view of the same, and FIG. 79 is a cross-sectional view showing an optical arrangement of the digital camera 40.

The digital camera 40, in a case of this example, includes the photographic optical system 41 (an objective optical system for photography 48) having an optical path for photography 42, a finder optical system 43 having an optical path for finder 44, a shutter 45, a flash 46, and a liquid-crystal display monitor 47. Moreover, when the shutter 45 disposed at an upper portion of the camera 40 is pressed, in conjugation with this, a photograph is taken through the photographic optical system 41 (objective optical system for photography 48) such as the zoom lens in the first embodiment.

An object image formed by the photographic optical system 41 (photographic objective optical system 48) is formed on an image pickup surface 50 of a CCD 49. The object image photoreceived at the CCD 49 is displayed on the liquid-crystal display monitor 47 which is provided on a camera rear surface as an electronic image, via an image processing means 51. Moreover, a memory etc. is disposed in the image processing means 51, and it is possible to record the electronic image photographed. This memory may be provided separately from the image processing means 51, or may be formed by carrying out by writing by recording (recorded writing) electronically by a floppy (registered trademark) disc, memory card, or an MO etc.

Furthermore, an objective optical system for finder 53 is disposed in the optical path for finder 44. This objective optical system for finder 53 includes a cover lens 54, a first prism 10, an aperture stop 2, a second prism 20, and a lens for focusing 66. An object image is formed on an image forming surface 67 by this objective optical system for finder 53. This object image is formed in a field frame of a Porro prism which is an image erecting member equipped with a first reflecting surface 56 and a second reflecting surface 58. On a rear side of this Porro prism, an eyepiece optical system 59 which guides an image formed as an erected normal image is disposed.

By the digital camera 40 structured in such manner, it is possible to realize an optical image pickup apparatus having a zoom lens with a reduced size and thickness, in which the number of structural components is reduced.

Next, a personal computer which is an example of an information processing apparatus with a built-in image forming system as an objective optical system is shown in FIG. 80 to FIG. 82. FIG. 80 is a frontward perspective view of a personal computer 300 with its cover opened, FIG. 81 is a cross-sectional view of a photographic optical system 303 of the personal computer 300, and FIG. 82 is a side view of FIG. 80. As it is shown in FIG. 80 to FIG. 82, the personal computer 300 has a keyboard 301, an information processing means and a recording means, a monitor 302, and a photographic optical system 303.

Here, the keyboard 301 is for an operator to input information from an outside. The information processing means and the recording means are omitted in the diagram. The monitor 302 is for displaying the information to the operator. The photographic optical system 303 is for photographing an image of the operator or a surrounding. The monitor 302 may be a display such as a liquid-crystal display or a CRT display. As the liquid-crystal display, a transmission liquid-crystal display device which illuminates from a rear surface by a backlight not shown in the diagram, and a reflection liquid-crystal display device which displays by reflecting light from a front surface are available. Moreover, in the diagram, the photographic optical system 303 is built-in at a right side of the monitor 302, but without restricting to this location, the photographic optical system 303 may be anywhere around the monitor 302 and the keyboard 301.

This photographic optical system 303 has an objective optical system 100 which includes the zoom lens in the first embodiment for example, and an electronic image pickup element chip 162 which receives an image. These are built into the personal computer 300.

At a front end of a mirror frame, a cover glass 102 for protecting the objective optical system 100 is disposed.

An object image received at the electronic image pickup element chip 162 is input to a processing means of the personal computer 300 via a terminal 166. Further, the object image is displayed as an electronic image on the monitor 302. In FIG. 40, an image 305 photographed by the user is displayed as an example of the electronic image. Moreover, it is also possible to display the image 305 on a personal computer of a communication counterpart from a remote location via a processing means. For transmitting the image to the remote location, the Internet and telephone are used.

Next, a telephone which is an example of an information processing apparatus in which the image forming optical system of the present invention is built-in as a photographic optical system, particularly a portable telephone which is easy to carry is shown in FIG. 83A, FIG. 83B, and FIG. 83C. FIG. 83A is a front view of a portable telephone 400, FIG. 83B is a side view of the portable telephone 400, and FIG. 83C is a cross-sectional view of a photographic optical system 405. As shown in FIG. 83A to FIG. 83C, the portable telephone 400 includes a microphone section 401, a speaker section 402, an input dial 403, a monitor 404, the photographic optical system 405, an antenna 406, and a processing means.

Here, the microphone section 401 is for inputting a voice of the operator as information. The speaker section 402 is for outputting a voice of the communication counterpart. The input dial 403 is for the operator to input information. The monitor 404 is for displaying a photographic image of the operator himself and the communication counterpart, and information such as a telephone number. The antenna 406 is for carrying out a transmission and a reception of communication electric waves. The processing means (not shown in the diagram) is for carrying out processing of image information, communication information, and input signal etc.

Here, the monitor 404 is a liquid-crystal display device. Moreover, in the diagram, a position of disposing each structural element is not restricted in particular to a position in the diagram. This photographic optical system 405 has an objective optical system 100 which is disposed in a photographic optical path 407 and an image pickup element chip 162 which receives an object image. As the objective optical system 100, the zoom lens in the first embodiment for example, is used. These are built into the portable telephone 400.

At a front end of a mirror frame, a cover glass 102 for protecting the objective optical system 100 is disposed.

An object image received at the electronic image pickup element chip 162 is input to an image processing means which is not shown in the diagram, via a terminal 166. Further, the object image finally displayed as an electronic image on the monitor 404 or a monitor of the communication counterpart, or both. Moreover, a signal processing function is included in the processing means. In a case of transmitting an image to the communication counterpart, according to this function, information of the object image received at the electronic image pickup element chip 162 is converted to a signal which can be transmitted.

As it has been described above, the image forming lens of the present invention, and the electronic image pickup apparatus in which the image forming lens is used have the following characteristics.

(1) It is characterized in that, instead of condition (1a), the following conditional expression is satisfied. 1.48<β<2.04 Here, Nd denotes a refractive index of a glass used in a cemented lens, νd denotes an Abbe's number for the glass used in the cemented lens, and a relation Nd=α×νd+β is satisfied. (2) It is characterized in that, instead of condition (1a), the following conditional expression is satisfied. 1.50<β<2.00 Here, Nd denotes a refractive index of the glass used in the cemented lens, νd denotes the Abbe's number for the glass used in the cemented lens, and the relation Nd=α×νd+β is satisfied. (3) It is characterized in that, instead of condition (2a), the following conditional expression is satisfied. 1.58<Nd<2.10 Here, Nd denotes the refractive index of the glass used in the cemented lens. (4) It is characterized in that, instead of condition (2a), the following conditional expression is satisfied. 1.63<Nd<1.95 Here, Nd denotes the refractive index of the glass used in the cemented lens. (5) It is characterized in that, instead of condition (3a), the following conditional expression is satisfied. 5<νd<10 Here, νd denotes the Abbe's number for the glass used in the cemented lens. (6) It is characterized in that, instead of condition (3a), the following conditional expression is satisfied. 6<νd<9 Here, νd denotes the Abbe's number for the glass used in the cemented lens. (7) It is characterized in that, instead of condition (1b), the following conditional expression is satisfied. 1.48<β<2.04

Here, Nd denotes the refractive index of the glass used in the cemented lens, νd denotes the Abbe's number for the glass used in the cemented lens, and the relation Nd=α×νd+β is satisfied.

(8) It is characterized in that, instead of condition (1b), the following conditional expression is satisfied. 1.50<β<2.00 Here, Nd denotes the refractive index of the glass used in the cemented lens, νd denotes the Abbe's number for the glass used in the cemented lens, and the relation Nd=α×νd+β is satisfied. (9) It is characterized in that, instead of condition (2b), the following conditional expression is satisfied. 1.60<Nd<2.10 Here, Nd denotes the refractive index of the glass used in the cemented lens. (10) It is characterized in that, instead of condition (2b), the following conditional expression is satisfied. 1.63<Nd<1.95 Here, Nd denotes the refractive index of the glass used in the cemented lens. (11) It is characterized in that, instead of condition (3b), the following conditional expression is satisfied. 5<νd<30 Here, νd denotes the Abbe's number for the glass used in the cemented lens. (12) It is characterized in that, instead of condition (3b), the following conditional expression is satisfied. 6<νd<0.25 Here, νd denotes the Abbe's number for the glass used in the cemented lens. (13) It is characterized in that, instead of condition (7), the following conditional expression is satisfied at the time of almost infinite object point focusing. 0.75<y ₀₇/(fw·tan ω_(07w))<0.94

where, y₀₇ is indicated as y₀₇=0.7y₁₀ when, in an effective image pickup surface (surface in which, image pickup is possible), a distance from a center up to a farthest point (maximum image height) is let to be y₁₀. Moreover, ω_(07w) is an angle with respect to an optical axis in a direction of an object point corresponding to an image point connecting from a center on the image pickup surface at a wide angle end up to a position of y₀₇.

(14) It is characterized in that, instead of condition (7), the following conditional expression is satisfied at the time of almost infinite object point focusing. 0.80<y ₀₇/(fw·tan ω_(07w))<0.92

where, y₀₇ is indicated by y₀₇=0.7y₁₀ when, in an effective image pickup surface (surface in which, image pickup is possible), a distance from a center up to a farthest point (maximum image height) is let to be y₁₀. Moreover, ω_(07w) is an angle with respect to an optical axis in a direction of an object point corresponding to an image point connecting from a center on the image pickup surface in a wide angle end up to a position of y₀₇.

The present invention can have various modified embodiments which fall within the basic teachings herein set forth

INDUSTRIAL APPLICABILITY

An image forming optical system according to the present invention is useful in an optical system with a reduced size and thickness (made thin), and furthermore, an electronic image pickup apparatus of the present invention is useful in an apparatus in which, both a favorable correction and a widening of an angle have been realized. 

1. An image forming optical system comprising: a positive lens group; a negative lens group; and an aperture stop, wherein the negative lens group is disposed at an image side of the aperture stop, and the negative lens group includes a cemented lens which is formed by cementing a plurality of lenses, and in a rectangular coordinate system in which, a horizontal axis is let to be Nd and a vertical axis is let to be νd, when a straight line indicated by Nd=α×νd+β (where, α=−0.017) is set, Nd and νd of at least one lens forming the cemented lens are included in both of areas namely, an area which is determined by a line when a lower limit value is in a range of a following conditional expression (1a), and a line when an upper limit value is in a range of the following conditional expression (1a), and an area determined by following conditional expressions (2a) and (3a) 1.45<β<2.15  (1a) 1.30<Nd<2.20  (2a) 3<νd<12  (3a) where, Nd denotes a refractive index, and νd denotes an Abbe's number.
 2. An image forming optical system comprising: a positive lens group; a negative lens group; and an aperture stop, wherein the negative lens group is disposed at an image side of the aperture stop, and the negative lens group has a cemented lens which is formed by cementing a plurality of lenses, and in a rectangular coordinate system in which, a horizontal axis is let to be Nd and a vertical axis is let to be ν, when a straight line indicated by Nd=α×νd+β (where, α=−0.017) is set, Nd and νd of at least one lens forming the cemented lens are included in both of areas namely, an area which is determined by a line when a lower limit value is in a range of a following conditional expression (1b), and a line when an upper limit value is in a range of the following conditional expression (1b), and an area determined by following conditional expressions (2b) and (3b) 1.45<β<2.15  (1b) 1.58<Nd<2.20  (2b) 3<νd<40  (3a) where, Nd denotes a refractive index, and νd denotes an Abbe's number.
 3. The image forming optical system according to claim 2, wherein when the one lens of which, Nd and νd are included in both the areas is let to be a predetermined lens, a center thickness of the predetermined lens along an optical axis of the predetermined lens is less than the center thickness along the optical axis of the other lens forming the cemented lens.
 4. The image forming optical system according to claim 3, wherein the image forming optical system satisfies a following conditional expression 0.22<t1<2.0 where, t1 is a center thickness of the predetermined lens along an optical axis of the predetermined lens.
 5. The image forming optical system according to one of claim 1 and claim 2, wherein the cemented lens is a compound lens which is formed by closely adhering and hardening a resin on a lens surface of the one lens which forms the cemented lens.
 6. The image forming optical system according to one of claim 1 and claim 2, wherein the cemented lens is a compound lens which is formed by closely adhering and hardening a glass on a lens surface of the one lens which forms the cemented lens.
 7. The image forming optical system according to one of claim 1 and claim 2, wherein the image forming optical system is a zoom lens of which, a lens group on the closest side of an object is a positive lens group.
 8. The image forming optical system according to one of claim 1 and claim 2, wherein the image forming optical system is a zoom lens of which, a lens group on the closest side of an object is a negative lens group.
 9. The image forming optical system according to one of claim 1 and claim 2, further comprising: a prism for folding.
 10. The image forming optical system according to claim 9, wherein the prism is in a lens group on the closest side of an object.
 11. An electronic image pickup apparatus comprising: an image forming optical system according to claim 1 or claim 2; an electronic image pickup element; and an image processing means which processes image data obtained by image pickup by the electronic image pickup element, of an image which is formed through the image forming optical system, and outputs as image data in which, a shape of the image is changed, wherein the image forming optical system is a zoom lens, and the zoom lens satisfies a following conditional expression at a time of an infinite object point focusing 0.7<y ₀₇/(fw·tan ω_(07w))<0.96 where, y₀₇ is indicated as y₀₇=0.7y₁₀ when, in an effective image pickup surface (surface in which, image pickup is possible), a distance from a center up to a farthest point (maximum image height) is let to be y₁₀. Moreover, ω_(07w) is an angle with respect to an optical axis in a direction of an object point corresponding to an image point connecting from a center on the image pickup surface in a wide angle end up to a position of y₀₇. 